Sony A77 Review

Overview

by Dave Etchells, Mike Tomkins, Zig Weidelich, and Shawn Barnett
Hands-on Preview Posted: 08/24/2011
Review Posted: 04/24/2012
Updated: 01/16/2013 (Performance page updated with v1.06 firmware and faster card)
Updated: 01/25/2013 (AF tracking tests added to Video page)

The primary leap is made possible thanks to the application of several technologies into a higher-end camera, chief of which is the Translucent Mirror Technology (TMT), which combined with use of an electronic first curtain, allows the Sony A77 to capture 12 frames per second with less noise and vibration. Until Sony's introduction of TMT, the fastest frame rate while maintaining full autofocus was found in the $5,000 Canon 1D Mark IV, which is capable of 10 frames per second while maintaining autofocus tracking.

Ergonomics. Plainly put, the Sony A77 feels and looks a lot like older enthusiast-level Canon SLRs. Not a bad design to emulate. I'm not saying it's a clone, or even intentional, but as one intimately familiar with Canon SLRs, the design makes me feel right at home; there are also elements that remind me of some Nikon models. While I liked the Sony A700's decidedly machine-like feel, the A77 feels more organic, and more in-tune with the rest of the SLR market. The grip is tacky and soft, very comfortable against skin. There's a nice relief to guide the middle finger into a comfortable position, and a gentle ridge rises inside the grip to give the tips of the fingers better purchase. It's necessary when the camera is combined with the rather heavy 16-50mm lens. That's not a complaint, by the way. Heavy is good when you want stability, and this combo captures such detail it needs the heft to work against constant, subtle human motion. Its heft is due partly to the magnesium alloy molded body shells front and back, and the 16-50mm f/2.8 lens also contributes noticeably to the weight of the Sony A77.

I find the shutter button a little high (higher than I'm used to from Canon SLRs), but that makes sense considering the Front control dial's position on the front of the grip. The tacky grip material wraps around to the rear, making an excellent thumbgrip.

One of the more pleasant finds on the Sony A77 is the AF-assist lamp. It's of a design that disappeared on Canon SLRs several years ago. It throws a red light, but one with a vertical line pattern that allows the camera to focus in complete darkness. It makes me wish Canon would bring it back; then again, here it is. There's also an infrared port nestled into the grip, a Depth-of-field preview button (not visible) lower left of the lens, and the AF mode selector dial.

The 16-50mm lens is a pleasure to behold and to use. Adhering to the straight, cylindrical design of other Sony lenses, the lens looks somewhat incongruous against the A77's smooth organic shape, but the two work together very well. The stout, perfectly ridged rubber rings turn smoothly, though the action requires a little more pressure than normal. It gives a sense of solid design, with tight weather-sealing and a robust internal mechanism. Though there's a lock switch to hold the lens at 16mm, I have yet to experience any lens creep. Point the lens down all you want, it won't creep. At least ours won't.

The mode dial is plastic with a knurled rubber band around it. It's comfortable to turn, and yet doesn't turn too easily for my taste. Front and rear control dials are also rubber, and both comfortable and responsive. Between the pop-up flash and hot shoe is a curved grille that conceals the stereo microphone. The grille is designed to minimize noise from the lens focus mechanism.

The Status LCD is handy to have, something the A700 lacked. All of the buttons are either smooth domes or concavities and give with clean, clear pops when pressed. Top deck buttons essentially mirror what you'll find on older Canon SLRs, including Drive mode, White Balance, ISO and EV. Since all of these are adjusted via the Status LCD, it makes sense. The shutter button has a fairly clear half-press, followed by uncertain mush. I quickly learned when it would fire, though, without a problem.

A thick, pliant rubber arches over the viewfinder opening. It's a little thicker than I'm used to from other SLRs, yet yields nicely as I press my glasses up against it for a better view of the OLED screen inside. A sensor over the opening turns on the OLED when your eye approaches. This is true whether you have the camera's LCD/EVF switch in Auto or Manual mode.

There's a gentle upward cant on the left of the Sony A77's bottom plate for a more comfortable hold while fingers reach out to control the lens.

I really like the joystick. Its sharp edge makes it easy to direct, while not tedious for the thumb. I liked the old one better, but this one seems less likely to break over time. An inward press on the button serves to make selections. All of the other buttons seem well-placed for easy access, though more than once I found myself pressing the AEL button instead of the Movie button when trying to record a movie.

The new swiveling LCD mechanism is at first novel, then a little befuddling, but once you learn just how to set it for different shooting situations, it's fine. I won't say it's necessarily better than other solutions, but it's not bad at all. First, like the Sony A65, the LCD is hinged at the bottom, where it can articulate down 180 degrees, then swing around 270 degrees. From there, a second horizontally articulating hinge nested in the A77's back plate swings out with a detent at 90 degrees, then it tilts up further about 80 degrees. A whole host of odd positions are possible, but only a few are useful on a regular basis. The LCD itself is a 921,600-dot display that is transflective, which means it's good indoors and in sunlight.

Shooting with the Sony A77

by Shawn Barnett

Right away, I could tell something was different. We'd heard the presentation, which sounded pretty good, but it wasn't until I held the Sony A77 that I knew something had changed. I felt the same way when I used the Sony A700, the camera the A77 replaces. I won't go too much into detail about my disappointment that the A700 went so long without an upgrade or successor; suffice it to say that I thought that camera was Sony's best chance at making a dent in the Canon/Nikon hegemony, and instead of addressing its few flaws, Sony was spending too much time trying to appeal to the consumer market, a place where Nikon and Canon dominate even more pervasively. I've long thought that to be successful in this market, Sony needed to impress the enthusiast first: Give them a real reason to switch, and some of the masses would begin to follow.

That reason, of course, appeared however stealthily in two other consumer cameras, the Sony A33 and A55: the Translucent Mirror Technology that enabled a high frame rate (7 and 10 fps) and continuous phase-detect autofocus from two sub-$1,000 cameras. But I wasn't sure these would get the attention needed to make a dent, worthy as the technology was. It just didn't seem like the message would get out, and the two cameras looked so much like EVF long zooms, I didn't think anyone would take them seriously. Despite that concern, searches for this line of cameras is reasonably high. But the real difference will come with the Sony A77. Capturing 24.3 megapixels at 12 frames per second changes everything. I haven't been this excited about a camera in some time, but based on my experience with the Sony A77, I'd buy one. 

I've already outlined most of the user experience at the top of this review. To recap: The Sony A77 is comfortable to hold and use, button placement is excellent, and its relative similarity to other SLRs on the market makes me feel right at home.

Viewfinder versus LCD. Sony's fundamental translucent mirror technology means there's no optical viewfinder to use when framing your images, so Sony draws a live image off the sensor and displays it on a relatively large OLED screen inside the viewfinder. The effect is more advanced than you're used to seeing from LCD electronic viewfinders. Instead of the distracting grid of pixels that normally greet your eye, the OLED in the Sony A77 is smooth and fairly high resolution.

It's pretty good for framing images when indoors, and it even gains up nicely to help you see detail that you can't see with your eye (though the refresh rate slows a bit). But outdoors it's a different story. While we normally turn to optical viewfinders and even EVFs in bright light, I find my eye taking a little more time to adjust to the OLED EVF in the A77's viewfinder. A sensor over the viewfinder detects my eye and makes the switch between the LCD and EVF, but usually doesn't make the switch fast enough, leaving me first in the dark, then I see a screen that's a little too dark at first, then my eye adjusts. It's not a comfortable set of changes, going from very bright to very dark, then to somewhat bright, so most often I and my colleagues shied away from the EVF when out in daylight, preferring the LCD.

Shadow detail. I got much better shadow detail than the optical viewfinder suggested.

The other problem I had with the electronic viewfinder is a tendency for shadows to appear plugged in high-contrast situations like the one at right. All of the foreground shadow was quite black in the EVF, which is partly why I took this shot: I wanted to see how the sensor would handle the deep shadows. Turns out the sensor did just fine, but I had discovered another limitation of the OLED viewfinder. Because I was thinking about the shadows, I don't remember if the sky in this shot was blown, another common problem among EVFs in high-dynamic-range situations.

Play. The Sony A77's quick nature is great for getting the family at play.

The good news is that the Sony A77's articulating LCD is excellent in both bright and dim light. Its 921,600 dots make another smooth image, one that seems to be transflective, or both transmissive and reflective. Sunlight striking its surface reflects back in relatively bright color that is quite a bit better than trying to read some LCDs through a dark cover-glass. Its unique swiveling mechanism is tough to describe, but I found myself using it a lot as I shot both cars and kids, because both benefit from shooting at a lower angle. At first it seems to be hinged at the bottom like past Sony designs, but then a horizontal hinge not unlike that used on Sony's NEX cameras swings out from the back, allowing the LCD a much greater range of motion. It can even face forward from the top or bottom. The joints are hinged with enough stiffness that the LCD stays where you leave it, so it's versatile. Figuring out which way to turn it for maximum effectiveness isn't obvious at first. When shooting low and vertically, I first swiveled the the LCD down, then to the right, so that the LCD faced upward with my right hand on the grip. However, it was often very difficult to frame images, because when I moved the camera left or right, the image moved in or out. The key is to use the second hinge. Swiveling that out presses the left edge of the LCD up against the EVF's rubber cup, and the image then matches: moving the camera left moves the image left, and moving right moves the image right.

Flash. The detail in this image is astonishing.

Subjects: Kids. In terms of close subjects, nothing moves faster than kids, except maybe butterflies. While my first thought of 12 frames per second was for capturing sports, having that high speed capture rate seemed perfectly logical when trying to capture a single good shot of my toddler. She's my most elusive subject. All my other children have been easy to photograph, but this little one is always changing. So when a single press on the shutter resulted in two or three shots almost instantaneously, I could see the potential; sadly the bright sunlight resulted in many squinty images instead of what I was looking for.

Droplets are plentiful in this shot, and you can even read his watch in the bottom shot.

I managed a shot with the pop-up flash, without the high-speed on. The lens hood of course cast a shadow on her left shoulder, but it's a good shot, with ridiculous detail. (Note that our Gallery images were taken with a pre-production beta unit. See our lab shots for production-level images.)

For action, I knew I could count on my son to keep moving and let me keep trying to catch him as he ran around the Centennial Olympic Park fountain. My favorite aspect of the Sony A900 was that it felt like you had captured the world in a snapshot so you could look at it in greater detail later at your computer. That's true of these two A77 shots as well. The water is frozen in the air, and a close-up reveals hundreds of tiny droplets as he splashes through the fountain. You can even look at his watch and see what time it was. The images are both underexposed, something I ran into occasionally with the prototype unit, but I prefer that to overexposure; the image looks great with a quick Levels adjustment in Photoshop, but as usual we try to post what the camera captures unmodified.

Sports. I had good positioning at a recent high school football game, and the Sony A77 combined with the f/2.8 70-200mm G were working as I'd hoped. Unfortunately, a storm rolled in right after the first quarter, so I didn't really get warmed up before lightning strikes ended the game (an all-too-common occurrence in Southern sports). Naturally I had the camera in 12 fps mode to see what I could capture. With all the refs and other players walking in front of the camera, it's not all that easy to get the nice shots you see in Sports Illustrated, nor is it easy to see that pigskin as the light fades, as it was doing while the storm rolled in. Still, with the Sony A77 set to ISO 800, I was able to capture one good sequence as the runner successfully sheds a determined defender.

12 fps. These three shots give you an idea of how well you can pick your moment at a sporting event. Here are links to the full-res images: YDSC00857.JPG, YDSC00858.JPG, YDSC00859.JPG

Focus starts a little soft on the runner's face in the first shot, perhaps because of motion on my part, but the other two are pretty crisp. I enjoy the determined expression on the runner's face. It's good detail for ISO 800.

I also caught a field goal kick for another example of 12 fps in action, which you can see in the Gallery. When the camera goes off it sounds really cool, but doesn't draw a lot of attention thanks to the lack of a mechanical mirror and the electronic first curtain. It's a very different sound from what you've heard on other cameras, and really serves up the images. You get a very brief preview of each image as it's captured, allowing you to track the subject well enough. As I saw the action in the game interrupted by a player or person on the sidelines I was able to ease off the shutter release, shooting short bursts that allowed me to follow longer plays reasonably well. At one point I did find myself running up against the buffer by the time the player reached the end zone, so celebratory touchdown shots were unavailable. Ultimately, you only have about a second of 12 fps if you just hold that shutter down, so you do have to learn to fire in short bursts. Perhaps they could program in a 3-shot burst mode, as are available in some machine guns for better buffer allocation.

Detail. The last 24-megapixel camera I reviewed was the Sony A900, and I took it to World of Coke in Atlanta, a museum to the sugary beverage's history. It's positioned in a location that offers a great view of the Atlanta skyline, right across from the Georgia Aquarium. Sony representatives more than once said that they thought the image quality from this new sensor rivaled that of full frame, so I made the same shot -- as close as I could -- within weeks of when I made the original shot (August 13, 2011 vs. August 31, 2008). The weather is remarkably similar, even if the lighting and time of day is different (note that the dates and times stamped into the A77's files are incorrect). It's very nearly a draw. Look at the crops below and see for yourself. At times the edge goes to the full-frame Sony A900, at times to the A77. At the outer edges of the frame, the 16-50mm lens shows a little softening, which you can see in the last crop below, but it's truly remarkable performance from a lens that effectively costs $600 when purchased as a kit, while the full-frame 24-70mm Carl Zeiss lens sells for around $1,750.  See our Sony DT 16-50mm F2.8 SSM review on SLRgear.com.

Sony A77 with 16-50mm f/2.8	Sony A900 with Zeiss 24-70mm f/2.8

Panorama. Surely people thought I was nuts holding an SLR while running the motor drive in a panning motion. A few even looked to see what action I might be following, but of course I was making a panorama, something I've done with other cameras at this site, but usually in a slower, more methodical way, capturing one shot at a time. Sony's Sweep Panorama makes it easy. I took several dozen sweeps at different times that afternoon, and you can see the best in the gallery. Ultimately I chose the one I made at sunset and cropped it. To get a good panorama with any camera, its best to shoot straight at the horizon line, something made easier thanks to the level function in the viewfinder and on the LCD. At sunset, that meant I captured a huge swath of lawn, darkened by the shade from the structures behind me. But it's such a large image that I was able to crop it down to just what I wanted.

I stepped back to get the cloud in this shot, but didn't want all the shaded grass up front. But I had a plan.

Back at the computer I cropped most of the grass and sweetened the colors a bit for a nice panorama.
Click on either image for a larger look.

AF tracking. Because the main purpose of the translucent mirror is full-time autofocus, we tested it as we have with other Sony SLT cameras, with a car driving at the camera at 30 miles per hour. Where results with the prototype model were a little spotty, our production sample delivered just exceptional focus accuracy and tracking: Virtually every frame was in sharp focus, even up to 40 mph, and the car as close as about 15 feet from the camera. This is just an exceptional level of AF tracking performance, the Sony A77 should have no trouble at with typical fast-breaking sports action. Video, though, was a rather difference experience, see the Sony A77 video page for details on what we found there.

Sony A77 Technical Info

by Mike Tomkins and Dave Etchells

Sensor and processor. At the heart of the Sony SLT-A77 is an impressively high-resolution 24.3 megapixel Exmor APS HD CMOS image sensor, whose output is handled by the latest version of the company's proprietary Bionz image processing engine. Total pixel count is some 24.7 megapixels, and the sensor's dimensions are 23.5 x 15.6mm, yielding a 1.5x focal length crop when compared with 35mm lenses. The SLT-A77's sensor has a standard RGB Bayer color filter.

With a 3:2 aspect ratio, the SLT-A77 can provide maximum image dimensions of 6,000 x 4,000 pixels at full resolution. Two further 3:2 aspect ratio resolutions are available: 4,240 x 2,832 pixels, or 3,008 x 2,000 pixels. The SLT-A77 also provides a choice of three 16:9 aspect ratio shooting modes, each of which has the same pixel width as its 3:2 aspect counterpart, but with heights of 3,376, 2,400 or 1,688 pixels respectively.

The Sony SLT-A77 offers a wide sensitivity range of ISO 100 to 16,000 equivalents, and the lower end of the range can be extended to ISO 50 equivalent. By default, sensitivities between 100 and 1,600 equivalents are also available through an Auto ISO setting, and this can be adjusted to encompass a range as wide as ISO 100 to 12,800 equivalents. High ISO noise reduction cannot be disabled altogether for JPEGs, but provides three adjustable operating strengths: High, Normal, or Low. Using the Multi-frame Noise Reduction function, you can specify the ISO sensitivity manually within an expanded range of ISO 100 to 25,600 equivalents, and the camera will average multiple exposures to create a single image with reduced noise levels.

Optics. The Sony A77 retains the same Alpha lens mount and translucent mirror design seen in the previous A33, A35, and A55 models. The company currently offers a selection of 33 Alpha mount interchangeable lenses, all compatible with the A77, and the camera will also accept historic Minolta or Konica Minolta Maxxum lenses.

The defining feature of the Sony SLT-series cameras, the translucent (or pellicle) mirror, allows most light to pass through to the imaging surface beneath, while a small portion is reflected for use by the camera's phase-detect autofocus sensor. This unusual design brings three main advantages over a traditional SLR: full-time phase detection autofocusing (even during video capture), improved burst shooting performance, and a modest reduction in camera body size.

The translucent mirror design has two main drawbacks, both related to its fixed transmission / reflection ratio. It requires use of an electronic viewfinder, since only 30% of incoming light is reflected by the mirror, and so a true optical viewfinder would be unusably dim. Also, with only 70% of incoming light received by the image sensor, Sony's SLT-series cameras aren't able to offer equal sensitivity / noise performance characteristics of a traditional SLR using the same sensor and image processing.

For photographers seeking high burst speeds or the ability to use phase detection AF during video capture, this is likely a trade-off they'll be willing to make, however. Some photographers may also consider the electronic viewfinder, which provides the ability to preview not only framing, but also functions such as white balance and creative effects, to be a positive as compared to an optical viewfinder.

Stabilization. As with its predecessors, the Sony A77 includes the company's SteadyShot sensor-shift image stabilization system. The current iteration of the system is now said to be good for a 2.5 - 4.5 stop correction, and is available with any mounted lens, regardless of focal length. (Some competitors rely on in-lens stabilization, which can provide better results at longer focal lengths, but which also potentially adds to the cost and size / weight of each lens purchased.)

Lens correction. When shooting in JPEG mode, the Sony SLT-A77 includes the ability to automatically correct lens shading (vignetting), lateral chromatic aberration, and distortion in-camera, as images are captured. At release, this feature was only available for four specific lens models: the SAL1650, SAL1855, SAL55200-2, and SAL18250, although Sony has since added support for additional 16 lens models via firmware updates.

Electronic viewfinder. Long time IR readers know that we've always been a little lukewarm toward electronic viewfinders (EVFs). To date, the tonal range, clarity, brightness, resolution, and update lag/refresh rates of EVFs have generally made them poor substitutes for the tried and true optical versions.

As technology continues to advance, though, many limitations of earlier EVFs are being addressed, and the OLED (Organic Light-Emitting Diode) technology used in the "TruFinder" found in Sony's latest Alpha and NEX models makes another large step in the right direction.

There's really more to say about the A77's OLED viewfinder than would fit here in this overview, so we've put a more complete discussion on its own page. A few quick notes are clearly in order here, though, as the viewfinder is such a large part of the Sony A77 experience.

Rich Information. The Sony A77's OLED "TruFinder" makes good use of its ample area. This is the view showing the most information; you can choose from a variety of displays, including one with no overlays on the image area.

Big, Sharp, Accurate. The first thing that strikes you about the A77's viewfinder is how big it is. If you're used to shooting with normal subframe SLRs, you're in for a pleasant surprise the first time you look through the A77's EVF. It's really more a size you'd expect to see on a high-end full-frame SLR selling for thousands of dollars more. It's also incredibly sharp; the first EVF we've seen with XGA (1,024 x 768) resolution; a staggering 2.4 million RGB dots. It also shows 100% of the frame area that the camera will capture; another feature more commonly associated with very high-end professional cameras.

Other Improvements, a couple of gripes. One of our biggest EVF gripes has been poor handling of highlight detail: It's often impossible to see what's going on with sky detail if you're shooting a landscape. The A77's TruFinder has some of the best highlight handling we've seen to date, but unfortunately gets into trouble at the other end of the tonal scale, with a tendency to plug dark areas of the image badly. Also, even at maximum brightness, the TruFinder isn't nearly as bright as a sunny day, so we found that our eyes sometimes took a few moments to adapt when we first looked through it when the surroundings were very bright.

We did feel that the TruFinder's update lag and refresh rate were considerably better than we saw on last year's A33 and A55, although it's still not quite up to the zero millisecond lag provided by an optical finder.

Finally, of course there are the things no optical viewfinder can do: For one, provide a true preview of the shot you're about to capture (including white balance and exposure), and for another offer an incredibly rich information display.

Bottom line, while we still like the visual experience of looking through an optical viewfinder, the Sony A77's TruFinder addresses a number of traditional EVF issues, and brings such a host of other benefits that we'd be happy to make the optical/EVF switch with it.

As noted, the foregoing is only a brief discussion of all the pros and cons of Sony's new OLED TruFinder; check out our A77 viewfinder page for all the details.

Displays. Like the A33 and A55 before it, the Sony SLT-A77 includes an articulated TFT LCD panel, but the articulation mechanism has been completely redesigned. Previously, the tilt/swivel mechanism was mounted at the bottom of the camera, meaning that although the LCD could be turned to face forwards, it wasn't visible from in front of the camera if shooting on a tripod or with the camera placed on a convenient flat surface. For a camera aimed at consumer and enthusiast use, we'd imagine that self-portraits and group shots in which the photographer is a participant are not an uncommon use case. The SLT-A77 corrects this oversight, with a tilt-swivel mechanism that now allows viewing from in front of the camera, as long as you're not using the popup flash or or a hot-shoe mounted external strobe.

The new mechanism has two separate hinges. The first of these folds the LCD downwards, and also includes a swivel mechanism, in much the same style as in the earlier cameras. However, instead of being fixed to the camera body, this assembly is affixed to a structure that's hinged halfway up the camera body, allowing the LCD and first hinge / swivel to fold upwards, presenting the panel at the top of the camera while providing just enough clearance for the viewfinder eyepiece. While it's definitely more versatile than the earlier mechanism, it's unfortunately still blocked for shots with on-camera flash, and we do wonder about its long-term durability, given the added complexity of the articulation mechanism. Hence we'd still consider the more traditional side-mounted tilt/swivel screens found on some competitors to be slightly preferable.

As for the panel itself, the basic specifications are also unchanged, with a three-inch diagonal, and a total resolution of 307,200 pixels (921,600 dots). The design includes Sony's TruBlack anti-glare technology, which couples a reinforced glass cover plate with anti-reflective film, and a resin filling that removes the air gap beneath the cover plate, thus improving contrast and reducing glare under harsh sunlight. There's also still an automatic brightness control with five-step manual override.

As well as its built-in color LCD panel, the Sony SLT-A77 also features a small monochrome LCD info panel on its top deck, providing quick confirmation of camera setup. It's also compatible with the company's optional CLM-V55 LCD panel accessory, a five-inch, 800 x 480 pixel display that attaches via the HDMI port, and includes a detachable hood to improve daylight visibility.

Focusing. The Sony A77 features a new 19-point CCD phase detection autofocus sensor, upgraded from the 15-point sensor used in its predecessors. The new chip greatly expands the number of cross-type focus points to eleven, up from three in earlier models. The A77's autofocus system has a working range of EV -1 to 18 at ISO 100 equivalent, with an f/2.8 lens attached.

As mentioned previously, one of the main advantages of Sony's Translucent Mirror cameras -- including the A77 -- is that this sensor can be used at all times, even during video capture. (Traditional DSLRs must switch to the slower contrast detection autofocus method during live view and video capture, or must interrupt the video feed to flip mirrors for a phase detect operation. Contrast detection is also used by all compact system cameras, with the exception of Sony's own NEX-series models when using Alpha-mount lenses with the optional LA-EA2 mount adapter.)

The SLT-A77 provides single-servo and continuous-servo autofocus operation, as well as an Automatic AF mode which switches between single and continuous types as the camera deems necessary, depending upon the subject. There's also both AF tracking and predictive control, and an AF microadjustment function that allows AF to be tweaked separately for 30 different lens types. A built-in LED autofocus illuminator helps the SLT-A77 to achieve a focus lock on nearby subjects in low ambient lighting conditions. The A77 also provides the ability to start autofocus operation instantly that you bring your eye to the electronic viewfinder, potentially reducing the time taken to achieve a focus lock

As you'd expect, it's also possible to focus manually with the Sony SLT-A77, either after an autofocus operation has been performed (Direct Manual Focus, in Sony parlance), or without any prior autofocus operation. When focusing manually, Sony offers two Focus Magnifier zoom levels to aid in determining the precise point of focus, either 5.9x or 11.7x. Also included is the "focus peaking" display which was introduced in the NEX-C3. This makes it easier to identify the point of focus by highlighting the areas of strongest image contrast. When enabled, three highlight colors are available (white, red, or yellow), and the peaking function can operate at one of three sensitivity levels (high, mid, or low.)

Performance. As well as allowing full-time AF during live view and movie capture, the translucent mirror design of the Sony SLT cameras brings another important advantage. During burst shooting with continuous autofocus, a traditional SLR has to drop its mirror between each frame, wait just long enough for any mirror vibration to settle, perform the AF measurement, and then raise the mirror again so that the next frame can be captured. Using a pellicle mirror, there's no reflex mirror to raise, and so the only delay required is to wait for the lens aperture to open after the exposure has been completed. For even swifter burst shooting, the aperture can be locked at either f/3.5, or the maximum aperture of the lens, whichever is smaller, removing the delay required to set and reset the aperture to allow focusing between shots.

Last year's SLT-A55 was already quite swift, especially with the aperture locked, but the SLT-A77 makes another significant step forwards in shooting speed. Indeed, Sony is claiming the SLT-A77 to be the world's fastest APS-C interchangeable-lens camera, as of August 2011. The standard Continuous Advance drive mode provides two burst-shooting speeds, the higher of which is manufacturer-rated at eight frames per second, up from six frames per second in the A55. (The lower-speed Continuous Advance mode is fixed at three frames per second, slightly faster than the 2.5 fps offered in the A55.) If you're willing to lock the aperture as noted previously by switching to Continuous Priority AE mode, though, you can shoot at a stunning twelve full-resolution frames per second, according to Sony. Again, that's a full two frames per second faster than the A55's spec, despite an increase in resolution from 16.2 to 24.3 megapixels.

Maximum burst depth in the Continuous Hi and Continuous Priority AE modes is rated by Sony as 13 raw or Extra Fine JPEG images, or 11 raw+JPEG frames. The Continuous Hi mode offers one more frame than is available for Continuous Priority AE mode when shooting Fine or Standard-compression JPEGs, achieving 18 frames with either compression level in Continuous Hi, and 17 frames in Continuous Priority AE according to the manufacturer spec.

The SLT-A77 also offers a prefocused shutter release lag of just 0.05 seconds, and although that doesn't quite match the 0.02 second release lag of the latest NEX-series compact system cameras in this area, that's again an exceptionally swift performance.

Visit the A77 Performance page for our timing and performance test results.

Dust reduction. Like the rest of Sony's SLT-series cameras, the Sony A77 includes a two-pronged dust abatement and removal system. First, a charge-protection coating on the low-pass filter aims to prevent dust adhering in the first place. Second, the sensor shift mechanism that's used to provide SteadyShot image stabilization also doubles as a shake mechanism to try and free stubborn dust particles that settle on the low-pass filter, although at much lower frequencies than the vibration induced by cameras using a piezoelectric element. From what we can tell, there is no strategy for keeping dust off the translucent mirror, except to blow the surface gently with air; it should never be touched. A fingerprint would likely require replacement at a service center. The mirror can be flipped up manually so that the sensor can be cleaned, though, just like any DSLR.

The SLT-A77's dust reduction system operates when the camera is switched off, which helps to reduce the startup time, while not relying entirely on the user remembering to manually trigger a dust reduction cycle. It is, however, possible to perform a cycle manually through the menu, if desired.

Environmental sealing. The Sony SLT-A77 includes dust and moisture-resistant seals throughout, including all the main buttons and dials, plus double-layered seals on the card slot, battery compartment, and terminals. The environmental sealing extends not only to the camera body itself, but also to the optional VG-C77AM vertical grip, HVL-F43AM external flash strobe, and the DT 16-50mm F2.8 SSM standard zoom lens, allowing a completely weather-sealed system. The weather sealing doesn't extend to other lenses in Sony's current lineup, however.

Exposure. The Sony SLT-A77 offers a choice of twelve basic operating modes, unchanged from the A55: AUTO, AUTO Advanced (AUTO+), Programmed AE, Aperture-priority, Shutter-priority, Manual, Memory Register (MR), Scene Selection, Sweep Panorama, 3D Sweep Panorama, Continuous Advance Priority AE, and Movie. Scene Selection will automatically set the camera up for one of eight common scene types, as selected by the photographer. Available scene modes are Portrait, Landscape, Macro, Sports Action, Sunset, Night Portrait, Night View, and Hand-held Twilight.

As in Sony's recent cameras, the Hand-held Twilight mode captures six sequential frames with higher sensitivity / shutter speeds to prevent blurring, and then combines them in-camera to yield a single frame with reduced noise levels. The Sweep Panorama modes each capture a burst of images for as long as the shutter button is held down, then automatically stitch them into a panorama. (The 3D mode generates a single image with separate left-eye and right-eye views of the scene, as the subject passes across the field of view). Memory Register mode allows three sets of shooting settings to be saved for later recall.

As with all Sony's Translucent Mirror cameras, the SLT-A77's performs exposure metering using its image sensor. The metering system in the SLT-A77 assesses the metered scene as 1,200 separate zones, and has a working range of EV -2 - 17 at ISO 100 equivalent, with an f/1.4 lens attached. Available metering modes include Multi-segment, Center-weighted, and Spot. As well as locking the metered exposure along with the focus when using multi-segment metering, there's also a dedicated Auto Exposure Lock button.. Exposure compensation is available within a range of 5.0 EV on either side of the metered exposure, in 1/3 or 1/2 EV steps, a much wider range than the +/- 2.0 EV available on earlier models. Additionally, the SLT-A77 can perform three-frame bracketed exposures with a step size of 1/3, 1/2, 2/3, 2, or 3 EV between shots, and five-frame bracketed exposures with 1/2, 1/2, or 2/3 EV between shots.

The Sony SLT-A77 offers a generous selection of thirteen white balance modes, including Auto, nine presets (Daylight, Shade, Cloudy, Incandescent, Warm White Fluorescent, Cool White Fluorescent, Day White Fluorescent, Daylight Fluorescent, and Flash), a direct color temperature setting (2,500 to 9,900 Kelvin), a color filter setting (15-steps of green to magenta bias, and 15-steps of blue to amber bias), plus a Custom white balance mode. There's also a white balance fine adjustment function available.

Available drive modes include Single-shot, Continuous Hi, Continuous Lo, Self-timer (with a delay of two or ten seconds), Continuous Bracketing, Single Bracketing, White Balance Bracketing, DRO Bracketing, and Remote Control (for use with the optional RM-DSLR1 infrared remote control unit). The aforementioned 12-frames-per-second Continuous Priority AE mode gets it own dial position.

Shutter speeds from 1/8,000 to 30 seconds are possible, and the SLT-A77 also offers a bulb shutter function that will hold the shutter open for as long as the shutter button is depressed. Flash sync is at 1/250 second. An optional long-exposure noise reduction function is available for exposures shot with shutter speeds longer than 1 second.

Sony tells us that the A77's shutter is now rated for a life of 150,000 cycles. This is very welcome; with its top continuous-exposure rate of 12 frames/second, those 150,000 cycles will go by faster than you might expect. (Just under three and a half hours of full-tilt 12fps continuous action.) The 150,000 cycle shutter life is on par with cameras like the Canon 7D and Nikon D7000 that the A77 is designed to compete with.

The most noticeable change in the A77's exposure system is its use of an "electronic first curtain." This improves performance while reducing noise and vibration, and is another very welcome addition.

Electronic First Curtain: Fast and quiet. A key technology in all Sony's August 2011 Alpha and NEX announcements is the "electronic first curtain" exposure capability. This greatly speeds the shutter release on live-view cameras, and significantly reduces shutter-generated vibration as well. A little explanation is perhaps in order.

In a conventional SLR, the focal-plane shutter is composed of two leaves or "curtains" that work together to control the exposure time. Think of your camera's sensor as a window with two windowshades; one rolling up from the bottom, the other rolling down from the top. The first curtain starts the exposure by dropping down to uncover the sensor. The second curtain ends the exposure by dropping down to cover it again. After each exposure, the shutter curtains are returned to their original positions in preparation for the next shot. Very short exposures are made by having the two curtains move together, moving a small slit across the focal plane.

To help you visualize, here are a couple of animations showing the action described above, one for a short exposure, the other for a longer one; once the graphic loads, click the button to see the shutter animation. (These animations are from Photocourse.com; check out their excellent Textbook of Digital Photography.)

In a live-view camera, the shutter curtains are initially open, so light can reach the sensor to create the live viewfinder display. In live view mode with a conventional mechanical shutter, the bottom curtain has to be raised first, before the exposure can begin. This of course takes time, increasing the shutter lag before the exposure can begin. The closing of the first curtain can also introduce additional vibration, affecting image sharpness at some shutter speeds. (See our detailed discussion of the blur anomaly in the original Olympus E-P1 for an example. The same issue exists to a greater or lesser degree in most mirrorless cameras, though it's all but invisible in some.)

What's new in this latest crop of Sony cameras is that the "first curtain" function is performed electronically. Rather than having to raise the shutter curtain before the exposure, the A77, A65, NEX-7, and NEX-5N all begin the exposure electronically, manipulating voltage levels on the sensor array to enable light-gathering in a progressive wave, sweeping down the sensor's surface.

The most noticeable result of this is that shutter lag in live view mode is very brief: Sony claims only 50 milliseconds (0.05 second), a number closely matching the 53.5 milliseconds we measured electro-optically in our lab. The reduced curtain movement also reduces shutter-induced camera vibration, and makes for a much quieter shutter release as well: The A77's shutter sound is unusually quiet. The electronic first-curtain capability is also likely part of how the A77 achieves its remarkable 12 frames/second continuous burst rate.

This isn't the first time we've seen an electronic first-curtain on an SLR: The Canon 40D introduced the concept back in August of 2007, and as far as we know, Canon live-view-capable SLRs still employ the technology. There's a significant difference in what we call prefocused release lag, though, with Canon's SLRs in Live View mode measuring in the range of 80-90ms, vs the 53.5ms of the Sony A77. In fact, the Sony A77's prefocused lag is very much on par with the fastest conventional SLRs, regardless of price range. Sampling a range of high-performance SLRs, we find shutter release times of 43ms for the Nikon D3s, 49ms for the Canon 1DmkIV, and 53ms for the Nikon D300s. While the Sony A77 doesn't have the absolute shortest release lag, it's very clearly in the top tier, regardless of price.

Tilt level. The Sony A77 includes a dual-axis level gauge, which helps ensure level horizons and prevent converging verticals in photos. The gauge is displayed in a style reminiscent of an aircraft attitude indicator, but with a separation of the roll and pitch indicators. When the camera is perfectly level, the pitch indicators and markings at the end of the roll indicator are illuminated in green.

Built-in GPS. Another less common feature of the Sony SLT-A77 is its built-in GPS receiver, which allows both images and movies to be tagged with information regarding capture location, such as latitude, longitude, altitude, etc. Tagged images can be displayed on a map showing their capture locations, either on a PC using the bundled Picture Motion Browser software, or on the Photo Map function of compatible Sony Bravia TVs. Of course, you can always use third-party software such as Adobe Lightroom or Picasa.

Face detection. Even among SLRs, face detection during live view is a fairly common feature these days. The Sony SLT-A77 goes a step further, though, in offering the ability to register the faces of eight specific individuals, who will then be automatically recognized and prioritized over other faces when determining focus, exposure, and flash output, as well as during post-exposure image processing. The SLT-A77 is capable of simultaneously detecting and accounting for up to eight faces in any given scene, and also includes a Smile Shutter function with three-step sensitivity, which will automatically capture an image when your subject is smiling. Of course, face detection can be disabled, should you wish.

Flash. The Sony SLT-A77 includes an auto-popup flash strobe, slightly improved from that in the A55. The guide number is now 12 meters (39.4 feet) at ISO 100, coverage is rated at 16mm, and the recycle time is rated at three seconds, as compared to the A55's guide number of 10 meters (32.8 feet) at ISO 100, 18mm coverage, and four-second recycle.

Available built-in flash modes include Off, Auto, Fill, Rear-sync, and Slow-sync, and an optional red-eye reduction function is available. Flash metering modes include ADI and pre-flash TTL, as well as manual output control being available (1/1, 1/2, 1/4, 1/8 or 1/16 power). +/-3 EV of flash exposure compensation is available, in 1/3 EV steps, and flash exposures can also be bracketed, with five frames varying by 1/3, 1/2 or 2/3 EV, or three frames varying by 1/3, 1/2, 2/3, 2, or 3 EV.

The A77's popup flash can also serve as a wireless controller. Some external strobes including the HVL-F36AM, HVL-F42AM, HVL-F56AM, and HVL-F58AM support high-speed sync and wireless shooting.

As with the earlier SLT-series cameras, the A77 also includes a proprietary flash hot shoe, but the pro-oriented SLT-A77 adds a standard PC sync terminal for connecting studio strobes. PC sync voltage supported is up to 400 volts.

Creative. The Sony SLT-A77 includes quite a range of creative controls to help photographers get the look they're after, with a minimum of time spent in the digital darkroom. A selection of eleven Picture Effect modes are available, five of them new since the SLT-A33 (with one mode having been removed.) The new modes include Soft High-key (which replaces the A33's High-key mode), plus Soft Focus, HDR Painting, Rich-tone Monochrome, and Miniature. The Posterization (color or black & white), Pop Color, Retro Photo, Partial Color (red, green, blue , or yellow), High Contrast Mono, and Toy Camera modes are all held over from the earlier camera. (The A55 and A35 also have the same Picture Effect modes as the A33 in current firmware, but didn't ship with this feature at launch.)

In addition, the SLT-A77 provides an enlarged selection of Creative Style choices as compared to the A55, each of which offers +/- three-step control over contrast, saturation, and sharpness. New Creative Style modes include Neutral, Clear, Deep, Light, Night Scene, Autumn Leaves, and Sepia, in addition to the existing Standard, Vivid, Portrait, Landscape, Sunset, and Black & White modes from the A55.

A Dynamic Range Optimizer function aims to open up the shadows while maintaining highlight detail, and can be left under automatic control, or set to one of five preset levels. There are also several multi-shot modes, including Hand-held Twilight (which allows faster shutter speeds with reduced image noise), and an Auto HDR mode. This last creates a single high dynamic range image from three sequential shots, whose exposure level varies anywhere from 1 - 6 EV in 1 EV steps, controlled automatically or manually.

The SLT-A77 also offers an in-camera Sweep Panorama function, which captures and stitches together multiple images as you sweep your lens across a panoramic scene. When set to Wide mode, Sweep Panorama can create a horizontal scene with a resolution of 12,416 x 1,856 pixels, or a vertical scene with a resolution of 2,160 x 5,536 pixels. In standard mode, the horizontal dimensions are 8,192 x 1,856 pixels, while vertical panoramas occupy 2,160 x 3,872 pixels.

3D Imaging. In addition to the standard Sweep Panorama function, the SLT-A77 includes a 3D Sweep Panorama mode. Since it only has objective lens, the stereo effect is created using some clever mathematics to reconstruct a 3D image as the subject passes across the lens' field of view. The result is saved as a single multi-picture object file that contains two separate JPEG images, one for each eye, allowing it to be viewed on 3D-capable Sony Bravia displays In Wide mode, 3D Sweep Panoramas occupy 7,152 x 1,080 pixels, while in Standard mode the resolution is 4,912 x 1,080 pixels. There's also a 16:9 mode, which saves a 1,920 x 1,080 pixel panorama suitable for full-screen HDTV viewing.

Video. The Sony SLT-A77 also offers Full HD (1,920 x 1,080 pixel) video capture capabilities, and according to Sony, is the world's first interchangeable-lens camera (along with other Sony models simultaneously announced) able to record Full HD off the sensor at 60 frames per second. (We've seen cameras previously which recorded 60 interlaced fields per second at Full HD resolution, but these either clocked the data off the sensor at 30 frames per second and then split each frame across two interlaced fields, or they clocked the data at 60 frames per second but discarded alternating fields, to be compliant with the original AVCHD 1080 60i specification.)

The SLT-A77's Full HD video is recorded using AVCHD Version 2.0 compression, with Dolby Digital (AC-3) audio, and a wide range of progressive-scan and interlaced frame rates are available. When set to NTSC mode, the available progressive-scan rate are 60 fps (28Mbps) or 24 fps (24 Mbps or 17 Mbps), and you can also opt for an interlaced 60 fps (24 Mbps or 17 Mbps). If you switch to PAL mode, the options are the same, except that the 60 fps rates are replaced by 50 fps equivalents, and the 24 fps rates by 25 fps ones.

It's also possible to record at a high-def resolution of 1,440 x 1,080 pixels (12 Mbps), or a standard-definition VGA (640 x 480 pixel, 3Mbps) resolution. These are all available at 30 fps in NTSC mode, or 25 fps in PAL mode, and are captured using MPEG-4 AVC (H.264) compression with MPEG-4 AAC-LC audio. Note that no 720p recording mode is available on the SLT-A77.

The most unusual capability of the Sony A77's video mode is enabled by its translucent mirror. The Sony A77 can continue to use phase detection autofocusing during movie recording, allowing swift adjustments to focus as your subject moves. Since standard Alpha-mount lenses are used, this focusing action is accompanied by significant levels of autofocus drive noise, although Sony notes that it has included a new noise reduction algorithm intended to suppress this AF drive noise. For consumers, any remaining drive noise is likely a relatively small price to pay for sharply focused video, however, given that manually pulling focus during video capture is a difficult art to learn.

Also unlike many competing cameras, the Sony SLT-A77 provides full control over movie exposure, with a choice of Program, Aperture-priority, Shutter-priority, or fully Manual recording. It also allows Tracking autofocus, as well as use of Creative Style and some Picture Effect modes during movie capture. Recording is started and stopped with a dedicated Movie button on the SLT-A77's rear panel, and audio is captured by default with a built-in stereo microphone. There's also an external stereo microphone jack, compatible with microphones including Sony's own ECM-CG50 Shotgun Mic and ECM-ALST1 Stereo Mic. A built-in monaural speaker caters to movie playback, and has an eight-step adjustable volume setting.

See the A77 Video page for sample videos and more details.

Playback. To let you immediately judge composition, exposure, and the like, the Sony SLT-A77 provides an optional Auto Review function that can display images on-screen for two, five, or ten seconds immediately post capture. (There's also a Shot Result Preview function in Record mode which lets you see an image as it would be captured with the current settings, including shutter speed, DRO settings, etc.) After capture, Playback mode lets you review single images, with optional shooting information, RGB histogram, or blinking highlight/shadow warning. In addition, images can be enlarged up to 13.6x to confirm fine details. Two index views are available, showing either four or nine frames at once.

Connectivity. The Sony SLT-A77 includes a USB 2.0 High Speed data connection, allowing for transfer of images and movies to a personal computer. Two operating modes are available for the USB connection, either USB Mass Storage Class, or Microsoft's Media Transfer Protocol. Catering for high-definition video output, the SLT-A77 also provides a Type-C Mini HDMI connection, with support for Bravia Sync, Sony's brand name for the Consumer Electronics Control standard. This allows certain playback functions such as switching between images to be performed using the attached display's remote control unit. There's no standard-definition video output on the SLT-A77, though, so photographers who've yet to switch to a high-def display will need a third-party device with which to view images on a standard TV.

Other connectivity on the SLT-A77 includes a DC Input for the optional AC adapter, a flash sync terminal and hot shoe, and jacks for both an external stereo microphone, and a wired remote control unit.

Storage. As well as Sony's proprietary Memory Stick PRO Duo and Memory Stick PRO-HG Duo flash cards, the SLT-A77's single card slot supports Secure Digital cards, including not only the higher-capacity SDHC and SDXC types, but also the higher-speed UHS-I compliant cards. 2D images can be saved either in Sony ARW 2.3 raw format, or as standard JPEG files (DCF Ver. 2.0, Exif Ver. 2.3, MPF Baseline compliant). 3D images are saved as Multi Picture Object files (MPF Extended compliant).

Battery. The Sony SLT-A77 draws power from a proprietary NP-FM500H lithium-ion battery pack, which is rated by Sony for 470 shots when using the electronic viewfinder, and 530 shots with the LCD monitor, to CIPA testing standards.

An available VG-C77AM vertical grip not only provides duplicates of the main controls for portrait-orientation shooting, but also accepts two NP-FM500H battery packs, roughly doubling battery life (since the in-camera battery pack can't be used with the grip connected).

Sony A77 Image Quality

Since the Sony A77 has now taken the APS-C resolution crown, we're comparing it here to two of its biggest competitors, the Canon 60D and Nikon D7000 and two full-frame cameras of similar resolution, in this case the Nikon D3X and Sony A850. Though we normally start with ISO 1,600 here, we thought we'd start with ISO 100 to show the best it can do.

Note: These crops have been updated from the original v0.58 firmware on our prototype A77 to v1.03 firmware from a full production-level unit. Also note that these images are best quality JPEGs straight out of the camera, at default settings including noise reduction. All cameras in this comparison were shot with our very sharp reference lens, the Sigma 70mm f/2.8 EX DG Macro.

Sony A77 versus Canon EOS 60D at ISO 100

Sony A77 at ISO 100	Canon 60D at ISO 100
The Sony A77 does quite well against the Canon 60D, which is not a huge surprise at ISO 100 considering what happens when you pit a 24.3-megapixel sensor against an 18-megapixel design. Both look great, but the Sony resolves more. You can see hints of a thread pattern in the Canon 60D, but it's better defined from the A77.

Sony A77 versus Nikon D7000 at ISO 100

Sony A77 at ISO 100	Nikon D7000 at ISO 100
The A77 also surpasses the 16.2-megapixel Nikon D7000, bringing out significantly more detail from our test target. What happens as ISO rises will be interesting.

Sony A77 versus Nikon D3X at ISO 100

Sony A77 at ISO 100	Nikon D3X at ISO 100
The Sony A77 also does well against the $8,000 full-frame D3X. The D3X looks a little more crisp, but simple sharpening could help that.

Sony A77 versus Sony A850 at ISO 100

Sony A77 at ISO 100	Sony A850 at ISO 100
Here we have the crop-frame A77 against Sony's full-frame A850. It seems to come down to a difference of contrast, maybe even exposure. The pink fabric below the red leaf swatch has more texture, which you'd expect from a larger sensor, and truer color. Overall, the A77 looks quite comparable.

Most digital SLRs will produce a reasonable ISO 100 shot, so we like to push them and see what they can do compared to other cameras at ISO 1,600, 3,200, and 6,400. Recent advances in sensor technology have made ISO 1,600 look a lot more like ISO 100, but there are still cameras whose quality starts to fall apart at this setting. We also choose 1,600 because we like to be able to shoot at least at this level when indoors and at night.

Sony A77 versus Canon 60D at ISO 1,600

Sony A77 at ISO 1,600	Canon 60D at ISO 1,600
ISO 1,600 confirms the reason we do these crops, as the Sony A77 starts to struggle with detail at this setting thanks to aggressive noise suppression, particularly in the mosaic crop. The Canon 60D maintains a little more detail, but not a lot, also struggling with the red leaf swatch. The A77 with the latest 1.03 firmware does a lot better in the red leaf swatch, producing a comparably muddled, if differently rendered image.

Sony A77 versus Nikon D7000 at ISO 1,600

Sony A77 at ISO 1,600	Nikon D7000 at ISO 1,600
It's probably a toss-up between the two, given the A77's heavier noise suppression against Nikon's lower detail at 16 megapixels. But there's no question that the Nikon D7000 renders the red leaf swatch a lot better than the Sony A77, even with the new firmware. Nikon still takes a more even hand balancing noise suppression against sharpening, creating a more realistic rendering than most other manufacturers at this point.

Sony A77 versus Nikon D3X at ISO 1,600

Sony A77 at ISO 1,600	Nikon D3X at ISO 1,600
Again, noise suppression in the A77 limits detail in all three crops when compared to the Nikon D3X, which has legendary performance in low light. Still, this is quite good performance from an APS-C sensor compared to a full-frame.

Sony A77 versus Sony A850 at ISO 1,600

Sony A77 at ISO 1,600	Sony A850 at ISO 1,600
Here the Sony A77 surpasses somewhat, doing a better job with background chroma noise and the mosaic image than its larger cousin the A850. But both the A900 and A850 didn't do as well at higher ISOs, so it's not much of a surprise. Note that the A850 still does a slightly better job on the red leaf swatch.

Today's ISO 3,200 is yesterday's ISO 1,600 (well, almost), so below are the same crops at ISO 3,200.

Sony A77 versus Canon EOS 60D at ISO 3,200

Sony A77 at ISO 3,200	Canon 60D at ISO 3,200
Except for color, it seems both cameras render about the same detail at ISO 3,200, though the A77 with the new firmware does a better job with the red swatch. The Canon retains a little bit more subtle color, if it's a little pumped by comparison. Very close.

Sony A77 versus Nikon D7000 at ISO 3,200

Sony A77 at ISO 3,200	Nikon D7000 at ISO 3,200
Sony cleans up the chroma noise a little more thoroughly, omitting color artifacts that show up noticeably in the shoulder of the olive oil bottle above in the D7000 image. But the Nikon D7000 looks a little better on the mosaic image, and does a better job capturing the essence of the red leaf swatch.

Sony A77 versus Nikon D3X at ISO 3,200

Sony A77 at ISO 3,200	Nikon D3X at ISO 3,200
The Nikon D3X maintains a lot more color as well as detail. The A77's rendering is still respectable, but again shows the disadvantage of a smaller sensor size.

Sony A77 versus Sony A850 at ISO 3,200

Sony A77 at ISO 3,200	Sony A850 at ISO 3,200
The Sony A77's image looks a little cleaner than that of the A850, with less blotchy noise, though the A850 renders the read leaf swatch a little better. I prefer the A77's image.

Detail: Sony A77 vs. Canon 60D, Nikon D7000, Nikon D3X, and Sony A850

Sony A77 ISO 100 ISO 3,200 ISO 6,400	Canon 60D ISO 100 ISO 3,200 ISO 6,400	Nikon D7000 ISO 100 ISO 3,200 ISO 6,400	Nikon D3X ISO 100 ISO 3,200 ISO 6,400	Sony A850 ISO 100 ISO 3,200 ISO 6,400
Detail comparison. High-contrast details are often sharper as ISO rises, so they're worth a look as well. Base ISO detail looks good from all five cameras, with the A77 looking slightly soft but not significantly so. The Nikon D7000 also doesn't quite render the lines inside the letters as well as the others due to its lower resolution of 16 megapixels. At ISO 3,200 you can see some decay in quality from the A77 even when compared to the A850, though the A850 shows color splotches where we know there are none. At ISO 6,400 the Sony A77 doesn't do quite as well as the others with the fine lines or the red letters. Still, for the price -- and even the camera's size -- the Sony A77 does very well.

Sony A77 firmware 0.58 vs 1.03

Below are crops comparing the red leaf swatch at ISO 3,200 with the prototype and production camera.

Sony A77 v. 0.58 at ISO 3,200	Sony A77 v. 1.03 at ISO 3,200
Sony's production firmware makes an improvement in the rendering of the very difficult red leaf swatch, so clearly they have improved their red-channel processing. There was little improvement in the other channels, so other elements of our test crops remained essentially unchanged.

Sony A77 Print Quality

100% crops on-screen can only tell you so much, especially when comparing cameras of different resolutions. So we always print samples of various sizes to determine the maximum print size at each ISO setting. To avoid printing massive stacks, we print only JPEGs generated from our test images taken at default noise suppression settings. Usually you can get quite a bit more processing the images from RAW.

Note: This is an updated print quality analysis based on images printed with the firmware version installed when the production-level lab shots were taken (v1.03), revealing a slight increase in overall quality from the pre-production version (v0.58) .

ISO 50/100 prints look quite good at 30 x 40 and terrific at 24 x 36.

ISO 200 prints are again excellent at 24 x 36 inches.

ISO 400 prints are also good at 24 x 36 inches.

ISO 800 shots print quite well at 20 x 30 inches.

ISO 1,600 shots look great at 16 x 20, although hints of noise appear in light shadows.

ISO 3,200 makes a nice 11 x 14 inch print, although there is some large, diffuse chroma noise in areas of flat tints.

ISO 6,400 images are usable at 8 x 10, if a little rough in some spots. We prefer the 5 x 7 images.

ISO 12,800 and 16,000 do not produce usable prints and are best avoided.

Overall, the Sony A77's image quality is excellent. Once we installed the updated firmware and reshot and printed the updated images, we were able to give slightly higher recommendations at several ISO settings than we were able to give with the prototype, based mainly on the update's ability to more accurately render data in the red channel.

In the Box

The retail kit contains the following items:

• Sony Alpha SLT-A77V body
• SAL1650 SAM lens with lens cap, if bought as a kit
• Lithium-ion battery pack NP-FM500H
• Battery charger
• USB cable
• Body cap
• Shoulder strap
• Software CD-ROM

Recommended Accessories

• Extra battery pack for extended outings
• Fast, large capacity SDHC/SDXC or Memory Stick Pro-HG Duo memory cards. These days, 8-16GB is a good trade-off between cost and capacity.
• Camera case
• Additional lens(es)
• External flash

Sony Alpha A77 Conclusion

The Sony Alpha A77 is a major leap forward for the company in DSLR design, features and image capabilities, finally putting Sony into the competitive mix with Canon and Nikon in the prosumer DSLR marketplace. The A77's 24.3-megapixel APS-C sensor, Translucent Mirror Technology and 12 frames-per-second capture rate changed everything for Sony. I found the Sony A77 to be solidly built, with a comfortable, familiar feel very reminiscent of the ergonomics of past Canon DSLRs-- which is a good thing. The A77 is very fast on almost all accounts, including autofocus, shutter lag and shot-to-shot speeds. As you'd expect with the high-resolution sensor, the A77's image (and print) quality is excellent, and the 16-50mm f/2.8 zoom kit lens provides excellent optics and performance beyond that of most kit lenses. Our laboratory testing did show that the A77's heavy-handed noise reduction robbed a little fine detail when shooting at ISOs of 1,600 and above. Another downside was the lack of an optical viewfinder. While the EVF does allow Sony to pack more performance into the sensor and internal electronics, I found it somewhat difficult to deal with; it was often dim when used in bright light, and didn't switch over from the LCD fast enough after it detected I was using the EVF. Additionally, when I took the camera out for some test shots, I found that sometimes my images were slightly underexposed, but nothing I couldn't fix afterward in Photoshop. Despite these negatives, I hadn't been excited about a DSLR as I was with the A77 in a long, long time. And Sony more than lived up to my high expectations. The rare combination of superior design and build, excellent imaging, fast shooting speeds, tons of creative modes, Full HD video recording and much more make the Sony A77 a definitive Dave's Pick.

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Design

Sony A77 Design

See below for call-outs of features and controls.

(Illustration courtesy Sony USA)

(Illustration courtesy Sony USA)

(Illustration courtesy Sony USA)

(Illustration courtesy Sony USA)

Optional VG-C77AM Vertical Grip
(Illustration courtesy Sony USA)

Operation

Sony A77 OLED Viewfinder

Hidden beauty. The new OLED-based "TruFinder" on the Sony A77 is key to its operation, addressing many limitations of past electronic viewfinders.

Long time readers know that we at IR always been lukewarm toward electronic viewfinders (EVFs). Happily, though, EVF technology continues to improve steadily, and the OLED (organic light-emitting diode) viewfinders on the A77, A65, and forthcoming NEX-7 represent another solid advance in the field. Optical viewfinders still can't be beat for clarity and brightness in some environments, but the OLED technology in Sony's latest viewfinders narrows that gap, and there are undeniably many ways in which Sony's new EVFs offer dramatically greater capabilities.

As we've looked back and edited this section, it struck us that there's an awful lot of discussion here about what is, after all, "just" a viewfinder. In defense of this, we think the EVF on Sony's translucent-mirror technology (TMT) and mirrorless NEX models will be a critical factor for a lot of traditionalists in deciding whether to make the move away from their old-style SLRs. Their electronic viewfinders are much more a key component of TMT cameras' value propositions than optical finders ever were in conventional models.

Tonal Range

One of our biggest gripes with EVFs has always been their limited tonal reproduction, particularly in highlight areas: It's enormously frustrating trying to frame a landscape shot with no idea of where the clouds are in the sky. Overall high-key subjects were always a challenge as well.

Sony's new OLED technology does a dramatically better job with highlights than most any EVF approach we've seen in the past, but we found that the tonal problem has now moved to the shadows: In scenes with a wide tonal range, it can be tough to see any detail in shadow areas without momentarily re-framing to get the viewfinder to gain-up a little.

We're optimistic, though, that this issue with tonal range might be addressed in firmware, perhaps even by the time the A77, A65 and certainly the NEX-7 reach market. A big feature OLED has going for it is an incredibly wide dynamic range. At the high end, you're of course limited with how brightly the little LED pixels can shine (more on that in a moment), but at the low end, when an LED is off, it's off: Zero current in means zero light out. By contrast (no pun intended), LCDs work by filtering light coming from a constant-brightness backlight, and so never get really black. So with an OLED, you have much more dynamic range to work with in the first place.

It seems to us that the problem with plugged shadows could be addressed fairly simply by just applying the right tone curve to image data being sent to the OLED unit. On the image-capture side, Sony has a very effective DRO (dynamic range optimizer) option that does a good job of balancing brightness between highlights and shadows. It even works when recording live video. Why not apply the same technology to these new OLED viewfinders, to boost shadow area brightness a little so you can see details?

We say we're optimistic that a firmware patch could better manage the OLED's tonal range, but it's possible that the camera hardware just isn't wired to provide for massaging the data flowing to the OLED chip. Let's all cross our fingers, and see what happens...

Brightness

Before turning to all the positive aspects of EVFs, I'll raise one other area where they lag behind optical viewfinders, namely image brightness compared to bright daylight. While I really fell in love with the Sony A77's EVF, it shared one remaining foible with lesser EVFs of the past. Even with the brightness adjustment set to maximum, when I brought the viewfinder to my eye while shooting under bright sunlight, the EVF display was significantly less bright than the surroundings. I often found it taking a moment for my eyes to adjust to the dimmer view, and I was conscious of pressing the camera particularly closely against my face in an attempt to block out as much ambient light as possible.

I don't know what the brightness limits of OLEDs are, so it's possible that Sony could change the settings to let the EVF get even brighter, but my guess is they'd already have done so if it were feasible. I personally didn't feel that the limited brightness was a major issue, but other IR team members who used the camera in bright sunlight found it rather distracting. (Happily, the transflective rear-panel LCD does well in bright surroundings; it worked very well, even in glaring direct sunlight.)

Sensitivity

Having spent more than my share of time griping, it's time now to turn to the positive aspects of EVFs, as evinced by Sony's OLED technology. One very useful improvement over optical viewfinders comes at the opposite end of the light scale, when shooting under dark conditions. The Sony A77's EVF does an excellent job of gaining-up when the light gets dim. There's no free lunch, in that the trade-offs are that the image gets a bit grainy looking, and the refresh rate drops dramatically, but the net result is I was much more able to see what I was shooting after dark with the A77 than I've ever been with any optical-viewfinder camera I've used in the past.

Wide open spaces. The Sony A77's OLED-based "TruFinder" really raises the bar on electronic viewfinders as a class. It offers a huge viewing area, with super-high XGA (1,024 x 768) resolution, and improved tonal range and refresh rate.

Size, Resolution, and Accuracy

The first thing you'll notice right off when first looking into the Sony A77's viewfinder is how big it is. Compared to the viewfinders on any other subframe camera, the view through the A77's is enormous. The view has to be a good 30-40% larger in both height and width than what you'll see on most any other subframe camera on the market.

Surprisingly, though, even with its extra-wide viewing angle, the Sony A77 maintains a surprisingly high eyepoint of 27mm from the eyepiece lens and 22mm from the eyepiece frame. As an eyeglass-wearer, I always appreciate a high eyepoint, and with the A77, I didn't feel that I had to mash the camera against my glasses to be able to see the full display. (I did find myself wishing that the A77's viewfinder projected a little further beyond the back of the camera, though: I was quite conscious of how much my nose pressed against the back of the camera. If I left the LCD screen facing outward, huge nose-prints were an ongoing fact of life.)

The second thing you may notice about the Sony A77's viewfinder is its incredibly high resolution. With XGA resolution (1024x768) and 2,359,296 dots, this is easily the highest-resolution EVF we've ever seen. I found I could make out pixels in the text and icons of the information displays if I squinted hard enough, but never had any sense of pixelation in the viewfinder image itself.

The third important visual characteristic of the Sony A77's viewfinder is its 100% frame accuracy. This is absolutely a what-you-see-is-what-you- get viewfinder; it shows you exactly what the sensor is seeing. This is a feature you just don't see in SLRs below professional-grade models, selling for a couple thousand dollars a pop. Making an optical viewfinder with 100% accuracy requires incredibly exacting tolerances, the kind of tolerances that really drive up manufacturing costs. With an electronic viewfinder, it's a relatively simple matter to show the full image that the sensor is seeing. You can get pretty close (98% based on our measurements) with high-end prosumer or low-level pro models like the Canon 7D or Nikon D7000, but they're still not 100% unless you switch to live view mode and accept the AF speed trade-offs that implies. While it's rarely a critical issue in the sort of shots I take personally, I find it annoying that the "through the lens" viewfinder doesn't show me exactly what the camera is going to capture. - So I'm a huge fan of 100% viewfinders, as long as it doesn't cost me another $1,000 in cost of the camera to get one.

Sony A77 Viewfinder Responsiveness: Update Lag and Refresh Rate

Sony's A55 and A33 translucent-mirror SLRs were true breakthrough devices when it came to high-speed continuous shooting at affordable prices, and the Sony A77 and A65 take that capability up another notch, with maximum frame rates of 12 and 10 frames/second respectively.

Despite their very high frame rates, though, we found it difficult to track and frame fast-breaking action with the A33/55, because the image displayed in the viewfinder was always that of the last frame captured, not what was currently happening in front of the lens. Looking through the viewfinder, we were thus always reacting to where the subject was 1/7 second (A33) or 1/10 second (A55) in the past. A tenth of a second may not sound like much, but with a fast-moving subject (and shooters like us unskilled at sports and action photography), it was enough to cause major problems with framing and tracking.

As I'm writing this, we don't have an A55 on hand to compare against the A77, but it appears to us that in high-speed mode, the A77 is still showing the last image captured, rather than the current "live" view. That said, we haven't been as aware of the update-lag problem as much with the A77; we felt more able to track fast-moving subjects with it than was the case with the A33/55. We'd have to spend more time with it in a sports-shooting environment to say for sure how much improved the A77 is over the A55 in this regard, but even if it's still displaying the just-shot images, decreasing the lag from 1/10 to 1/12 second would be a help.

When not in continuous shooting mode, viewfinder responsiveness is a function of refresh rate; essentially the frame rate of the "live movie" that constitutes the viewfinder image. Specs for this are almost never published, in part because the refresh rate is usually a strong function of the amount of light falling on the camera's sensor. In dim lighting, the camera needs longer exposure times for each frame of the movie it's capturing and playing into the viewfinder display, setting an upper limit on the viewfinder's refresh rate. Indeed, as noted above, the Sony A77's refresh rate drops pretty dramatically when faced with very dim shooting conditions. (A trade off we're happy to accept, given that the resulting viewfinder image is much more visible than that from an optical viewfinder under similar circumstances.)

We don't have any way to measure the Sony A77's viewfinder refresh rate under bright lighting conditions, but our sense is that it's quite high: Motion was very smooth and fluid, and we had no sense of a delay or lag between the subject's motion and what we were seeing in the viewfinder.

Low refresh rates were often a bugaboo of early EVFs, but the problem seems pretty completely banished with the combination of the Sony A77's sensor, fast processor, and OLED EVF technology.

Sony A77 Information Display

The area where EVFs completely crush optical viewfinders is of course in on-screen information display. With the whole viewfinder area a full-color high-resolution image display, readout, status and other information can be displayed anywhere you please. Not only that, but full menu displays are a button-press away, so your eye never need leave the viewfinder while operating the camera.

Another often unrecognized advantage of an EVF is that, because the same display is being used for both the viewfinder image and AF point indicators, there's never a problem with ambient light washing out illuminated AF-point displays, or conversely there not being enough light to see ones that are just an LCD overlay. We found the AF point indicators on the A77's EVF particularly well designed. The Sony A77's AF point markers consist of open green squares with thin black outlines around them. The combination of bright and dark elements means active AF points are easy to see regardless of subject brightness: In bright areas, the black outlines make them stand out, while in dark areas, the green lines are easily visible.

Like the A33 and A55 before it, the Sony A77 makes great use of its EVF for information display. A host of basic camera setting and status information is always visible above and below the image area, and thanks to the unusually large viewing angle, the info displays don't cramp the viewfinder image at all. A lot of optional information that can be displayed as well: A shooting display mode provides data for 13 other camera settings overlaid on the viewfinder image, down the left and right sides; a histogram option displays an exposure histogram overlay in the lower right; a graphic display mode overlays virtual shutter speed and aperture indicators, also in the lower right; and a digital level gauge option overlays a red/green two-axis tilt meter in the center of the frame.

My response to the rich information environment of a well-constructed high-resolution EVF like the Sony A77's reminds me a little of my initial transition to all-digital photography 8 or 9 years ago now. Back then, I didn't realize how much I'd come to appreciate and even depend on the immediate feedback digital offered until I tried taking a trip with only my trusty film SLR in hand. With all my images locked up in film cans, I felt crippled and resolved "never again:" The next trip and ever after, it's been digital all the way.

I'm finding my experience with Sony's rich EVF environment somewhat similar. My everyday SLR (now an incredible 5 years old; definitely time for an upgrade) is a conventional optical-finder model. After using the Sony A77 for a few days, it feels crippling and archaic to go back to the sparse information provided by an old-style optical viewfinder.

Image Preview

Another feature that's of course not even possible with an optical viewfinder is true image preview. Not only are optical viewfinders generally limited in their framing accuracy, they have no way to show what sort of image the camera is about to record: You have no idea in advance of the shot whether the white balance is suitable, how the exposure is looking, etc. And while an optical viewfinder can give you a pretty good depth of field preview, if you're stopping down the lens much at all, the view will likely be too dark to make out the subject, let along judge relative focus.

The Sony A77 Viewfinder: Bottom Line

Much though I'm sure Sony would like me to agree with them that the A77's EVF finally matches all the desirable characteristics of an optical viewfinder, I'm afraid that time hasn't yet arrived: While great progress has been made, even the A77's OLED display doesn't come close to providing the dynamic range of a purely optical system. Likewise, update lag during continuous shooting is still at least somewhat an issue.

That said, though, I can confidently say that all the benefits the Sony A77's EVF brings over optical systems would leave me entirely comfortable switching over to it from my old-school optical-VF SLR without looking back.

Ultimately, the choice of optical vs EVF will come down to personal preferences, so you'll probably want to look through one yourself before making a final decision. For most people, though, I think the benefits of an EVF like the Sony A77's will far outweigh the few remaining limitations.

Viewfinder Test Results

Coverage
Excellent viewfinder accuracy.

The Sony Alpha A77's electronic viewfinder and LCD monitor both showed essentially 100% coverage with our reference Sigma 70mm f/2.8 prime lens, which is excellent.

Optics

The Sony A77 features a bayonet lens mount, which accommodates a range of Sony and Konica Minolta lenses. The Sony A77 optionally comes bundled with a Sony DT 16-50mm F2.8 SSM standard zoom lens, which our sister site SLRGear.com felt to be a capable walk-around zoom. The lens features a built-in focus motor for fast, quiet autofocus, and is designed to be used with subframe Sony SLRs. For detailed test results, see our review of this lens on SLRgear.com.

A small button on the front of the camera releases the lens from its mount, so it can be turned and removed. The A77's CMOS image sensor is smaller than a frame of 35mm film, so the angle of view at any given focal length will not be the same as on a 35mm camera. To find the approximate 35mm equivalent focal length, multiply the focal length of the lens by 1.5. (Thus, a 16-50mm lens will provide about the same view as a 24-75mm lens on a 35mm camera.)

Alpha lens mount. The Sony A77's Alpha lens mount is compatible with the full array of Alpha lenses, both screw-drive and electronic autofocus models.

The Sony A77 provides both manual and automatic focus control modes, set by the Focus Mode dial on the left side of the camera's front panel, unless the lens itself has a Focus Mode switch. If there's a duplicate switch on the lens, then both must be set to allow autofocus; that is to say that if either control is set to manual focus, then the setting of the other control will be ignored. The dial on the body provides more control than that on the lens, however. Instead of simply enabling or disabling autofocus, it's also used to set the AF mode to either Single-shot AF, Automatic AF, or Continuous AF. Single-shot sets focus with each half-press of the Shutter button, while Continuous mode is constantly adjusting the focus, whether the Shutter button is pressed or not. The Automatic setting will lock focus on a still subject or continually adjust focus on a moving subject, for as long as the Shutter button is halfway pressed.

The Function button provides access to Autofocus Area options, of which there are four choices: Wide, Zone, Spot, and Local. The default option is a 19-point Wide Focus area, with AF point locations indicated by small squares visible through the electronic viewfinder or on the rear-panel LCD display. Note that of the 19 AF points, only eleven utilize a cross-type sensor sensitive to detail in both the horizontal and vertical axis, with the other eight line-type sensors being sensitive to detail in one direction only. Wide AF bases its focus on the most prominent subject detail in the portion of the image that falls within the AF brackets, and the A77 can indicate which individual AF points achieved a focus lock by highlighting those points in green on either the electronic viewfinder or LCD while the shutter button is half-pressed.

In Zone mode, the AF points are addressed in one of three groups: either a group of seven points in a column near the horizontal center of the frame, or one of two clusters of six points in the left or right of the frame. The camera will still automatically choose one or more points at which to achieve a focus lock, but it will restrict itself solely to point in your chosen group while doing so. In Spot mode, the A77 uses only the centermost AF point, and only this point is indicated by a square target box in the center of the viewfinder or live view display. Finally, Local mode is Sony's terminology for a manual AF area selection, also known as Flexible Spot in some earlier models. This lets you manually set the main AF point by using the Multi-controller to highlight one of the 19 available AF points. The active AF area is given a bolder line in the viewfinder and live view displays, and is again highlighted in green upon focus lock as a visual reminder of which point was manually selected.

A couple of the more unusual features of the Sony A77 are its Face Detection and Smile Shutter functions. Face Detection can detect up to eight faces simultaneously within the image frame, and adjusts focus, exposure, image processing, and flash output. Detected faces are indicated with gray frames, which turn white when they fall under an autofocus point. When focus lock is achieved, the camera indicates which faces it feels were correctly focused with a green frame. When no faces fell under a phase detection sensor, the A77 reverts back to showing the AF points that achieved a lock, instead. Optionally, you can program the camera to recognize the faces of up to eight specific individuals, who will then be prioritized over other faces whenever they're recognized in the image frame. Smile Shutter, meanwhile, can be used to trip the shutter automatically when a smile is detected. You can adjust the "sensitivity" of Smile Shutter to either "Slight", "Normal", or "Big" smile, and a gauge at the left of the screen shows the degree of smile that the A77 is currently detecting, along with a mark indicating the point at which the shutter would be triggered.

A depth-of-field preview button can be found adjacent to the grip, at the base of the lens mount. When held in, the A77 stops down its aperture to the selected value, allowing preview of the depth of field available in the scene. The function is rather more useful than in the typical SLR, however, in that while the view through the electronic viewfinder will dim while the aperture is stopped down beyond the camera's ability to correct for, the camera otherwise adjusts preview sensitivity to attempt to show the image with correct brightness. This makes it quite a bit easier to gauge depth of field with small apertures in good light (but perhaps makes the preview image grainier in low light conditions).

Sony A77 AF Assist

The Sony A77 has a dedicated AF assist lamp, based around a bright red LED that projects a vertical line pattern, providing some high-contrast edges for easier and more accurate focusing on nearby subjects in dim lighting. This has two advantages over the more common flash-based AF assist on cheaper SLRs: it functions regardless of whether your flash strobe is raised, and doesn't dazzle your subject quite as much, so it's less likely to cause a blink.

Sony A77 Anti-Shake

The Sony A77 also employs Sony's SteadyShot Inside anti-shake technology, which uses a highly sensitive accelerometer, and a moveable platter on which the CMOS sensor assembly is mounted. Together, these allow the A77 to counteract camera movement with movements of the image sensor, rather than the more common approach of moving an optical element inside the lens.

Depending upon shooting conditions and the lens type attached, Sony claims that the SteadyShot Inside anti-shake system in the A77 provides anywhere from a 2.5 to 4.5-stop reduction in the blurring produced by camera shake. Translating that into real-world shutter speeds, a two-stop improvement means that a shutter speed of 1/30 second would give you the same resistance to blur from camera shake that a speed of 1/120 would without anti-shake. A 4-stop improvement would mean you could shoot as slow as 1/6 second and get the same results (blur-wise) as when shooting at 1/120 second unaided. Even the lower end of the specified range of effectiveness means a pretty significant improvement in one's ability to hand-hold long exposures.

Sony A77 Anti-Dust Technology

To help combat dust particles on the CMOS sensor from changing lenses, Sony has included both an anti-static coating on the low-pass filter and uses the sensor shift mechanism to automatically shake dust free each time the camera is shut off. There is also a manual cleaning mode, where the camera triggers a longer burst of sensor shift shaking. We've generally found dust-removal systems based on cameras' anti-shake systems less effective than those that use an vibrate the sensor ultrasonically, but it bears noting that no dust removal system completely eliminates the need for occasional manual sensor cleaning.

Sony A77 Optical Test Results

Below are the results of our optical tests of the Alpha A77 with the Sony DT 16-50mm f/2.8 SSM kit lens. The test images shown on most other pages of this review were taken with very sharp references lenses, so we use this page to explore kit lens quality.

Lens Test Results

Zoom
Good performance with the 16-50mm f/2.8 lens.

The Sony Alpha A77 is available bundled with the DT 16-50mm f/2.8 SSM lens. This lens possesses a typical optical zoom ratio of about 3.1x, but is wider than most with a 35mm equivalent focal range of about 24-75mm. Performance at wide-angle was good though overall detail is just a touch soft at f/8. Some blurring is visible in the corners, as well as some minor coma distortion, though chromatic aberration is very low because the camera suppresses it. There's also a small amount of flare around the building's white surfaces. Performance at 35mm was also quite good, with very good contrast and good sharpness across most of the frame. Results at the 50mm setting were similar, just a hint soft in the center and a bit softer in the corners. The Sony A77 offers 1.4x and 2x "Smart Teleconverter" digital zoom settings, which just crop so there's no image degradation, though the resulting images are smaller. Still, with a total of 24 megapixels on tap, the cropped images are quite useful. (1.4x results in 12-megapixel images, while 2x produces 6-megapixel files.) Overall, a good performance from a premium kit lens.

Macro
A larger than average sized minimum coverage area, with good detail. Flash was a bit bright but throttled down reasonably well, though lens casts a shadow.

As with zoom performance, the Sony Alpha A77's macro performance will depend entirely on the lens in use. However with the 16-50mm kit lens set to 45mm, the Sony A77 captured a larger than average sized minimum area measuring 4.76 x 3.18 inches (121 x 81 millimeters). Detail was pretty good, just a touch soft in the center of the frame at f/8, but corners weren't much softer. (Most lenses have some softening in the corners at macro distances, so the 16-50mm lens did better than average here.) Auto white balance was quite warm and yellowish with our ambient lighting, though. The flash did a pretty good job throttling down, though the lens casts a shadow, leading to a very uneven exposure.

Geometric Distortion
Higher than average geometric distortion at wide-angle.

Complex barrel distortion at 16mm is about 1.0 percent

Pincushion distortion at 50mm is about 0.2 percent

The Sony Alpha A77's 16-50mm kit lens produced about 1.0 percent of complex barrel distortion (moustache-shaped) at wide-angle, which is higher than average and noticeable in some of its images. At the telephoto end, we measured just under 0.2% pincushion distortion, which is not very noticeable in images. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).

Chromatic Aberration and Corner Sharpness
Low to moderate chromatic aberration in JPEGs. The lens produced some soft corners at both zoom settings.

Aperture: maximum
16mm@f/2.8: Upper left C.A.: Moderate Softness: Moderate blurring	16mm@f/2.8: Center C.A.: Low Softness: Sharp
50mm@f/2.8: Upper left C.A.: Low Softness: Slight blurring	50mm@f/2.8: Center C.A.: Very low Softness: A touch soft

Chromatic Aberration. Chromatic aberration in the corners with the Alpha A77's 16-50mm kit lens at wide-angle (16mm) and maximum aperture was moderate in terms of the number of pixels, so the effect was noticeable in a few shots. At full telephoto (50mm) and maximum aperture, chromatic aberration was less noticeable, with only faint coloration.

Corner Softness. Wide-open at full wide-angle, the 16-50mm kit lens was moderately soft in the top left corner, while other corners were considerably sharper. The softness didn't extend very far into the frame, though, and the center was quite sharp. At full telephoto, all four corners showed only slightly blurring, while the center was just a touch soft with lower contrast than wide-angle. You can also notice some minor vignetting (corner shading) from the darker corner crops, but it's really quite low.

Aperture: f/8
16mm@f/8: Upper left C.A.: Moderately low Softness: Slightly soft	16mm@f/8: Center C.A.: Low Softness: Sharp
50mm@f/8: Upper left C.A.: Low Softness: Slightly soft	50mm@f/8: Center C.A.: Very low Softness: Sharp

Chromatic Aberration. With the lens stopped down to f/8, chromatic aberration in the corners at wide-angle (16mm) was moderately low, better than wide-open, and in the center it was quite low. At full telephoto (50mm), chromatic aberration was again low in the corners, and very low in the center.

Corner Softness. Corner sharpness improved at wide-angle at f/8, though corners were still a bit softer that the center. Interestingly, at telephoto some corners were a bit softer stopped-down to f/8 than there were wide open, though the center was fairly sharp. Vignetting was low at wide-angle, and negligible at telephoto.

Overall, a good performance for a kit lens, especially considering the A77's resolution.

Lens Corrections

When shooting in JPEG mode, the Sony Alpha A77 includes the ability to automatically correct or improve geometric distortion, chromatic aberration, and lens shading (vignetting) from supported lenses, as images are captured.

Geometric Distortion

Barrel distortion at 16mm is less than 0.2 percent

Pincushion distortion at 50mm is lens than 0.1 percent

Above, you can see with Distortion Correction enabled (set to Auto), the kit lens shows significantly less distortion (<+0.2% at wide-angle, <-0.1% at telephoto) than with it disabled (+1.0% at wide-angle, -0.2% at telephoto). The default setting is Off.

Chromatic Aberration

CA Correction Auto	CA Correction Off
16mm@f/2.8: Lower right C.A.: Moderate	16mm@f/2.8: Lower right C.A.: High and bright
50mm@f/2.8: Lower right C.A.: Low	50mm@f/2.8: Lower right C.A.: Also low

Above, you can see a significant increase in chromatic aberration at wide-angle with CA Correction disabled, though the difference at telephoto is minimal because CA is low at telephoto to begin with. The default setting for this correction is Auto.

Peripheral Shading

16mm @ f/2.8
Auto	Off

Mouse-over the links above to see the difference Peripheral Shading correction makes at wide-angle when wide-open at f/2.8 (the worst-case scenario for most lenses). The default setting is Auto.

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Sony Alpha SLT-A77 Photo Gallery .

Exposure

The Sony A77 offers all the same exposure options you'd expect in a mid-range SLR camera, plus a few Sony-specific options. Available exposure modes include Program AE, Aperture Priority, Shutter Priority, and Manual modes, with shutter speeds from 1/8,000 to 30 seconds, as well as a Bulb setting available in Manual mode only, for longer exposures. The x-sync speed for flash photography is 1/250 second. A fully automatic mode places the camera in control of almost all functions, to try to deliver optimum results under a wide range of conditions. Another mode called Auto+ is similar to standard Auto, but has scene recognition that allows it to automatically select one of a dozen different scene types, some of which can't be directly accessed from the Scene mode. Basic options such as exposure compensation aren't available to the photographer in either of the Auto modes, but the A77 will still allow you to select from a subset of drive modes and flash modes, lock exposure with the AEL button, focus manually or automatically, and enable or disable the face detection and smile shutter functions.

The Sony A77's Mode dial also includes a Scene position, offering access to including Portrait, Sports Action, Macro, Landscape, Sunset, Night Scene, Hand-held Twilight, and Night Portrait. There's also a separate Sweep Panorama mode that captures and stitches a multi-image panorama with a single press of the shutter button, and merits its own position on the dial. So does a 3D Sweep Panorama mode, which operates similarly, but simulates a 3D effect with some clever maths. A Continuous Advance Priority AE mode locks the lens aperture at either F3.5, or the maximum aperture of the lens, whichever is smaller, removing the delay required to set and reset the aperture to allow focusing between shots. This enables the camera's fastest burst-shooting performance of 11.6 frames per second, according to our in-house testing. Finally, there's both a Movie mode that enables capture of videos with manual control over exposure variables, and a Memory Recall mode that allows three different groups of camera settings to be saved for later recall.

The Sony A77 offers an optional live histogram function in all operating modes. Located near the bottom right corner of the LCD panel or electronic viewfinder display, it's rather small, and offers only a luminance readout rather than a full RGBY histogram, but it's still very useful for ensuring your exposures are correct. Another feature that's rather more common, but still very welcome, is the exposure display when the camera is in Manual exposure mode. This shows the amount the camera thinks an image will be over- or underexposed within a range of +/-2.0EV, based on the settings you have selected, to help you find the best exposure for the subject. (Beyond the 2.0EV range, arrows on either end of the scale blink in the viewfinder, and the value blinks on the rear-panel LCD, to emphasise that the metering system's limit has been reached.) Together, the live histogram and exposure display make it relatively easy to get suitable exposures even when shooting manually.

Sony A77 Face Detection / Recognition
The Sony A77 includes Face Detection capability, capable of locating up to eight faces in the scene simultaneously. This information is taken into account when determining several exposure variables -- focus, exposure, flash and white balance. The A77 goes a step further than some competing models, and can also be programmed to recognize up to eight specific individuals, who are then prioritized over other detected faces when they're detected in the scene. It also offers another related feature that is now commonplace in point-and-shoot cameras, but still relatively unknown in large-sensor cameras. Dubbed "Smile Shutter", this allows the A77 to automatically trigger the shutter, capturing photographs by itself when a smiling face is detected within the image frame. The A77's implementation is perhaps best suited to portraits of individuals, since the shutter is tripped when only one face within a group is smiling. There's a three-step control over the degree to which a subject must smile before the shutter is tripped. and when Smile Shutter is enabled, the A77 also provides a graph at the left of the screen that indicates how close a particular expression has come to passing the required threshold for the shutter to be tripped. It doesn't, however, offer the blink detection function that's equally common in compact cameras.

Sony A77 ISO Range
ISO sensitivity ranges from 50 to 16,000, which would have been considered a very wide range just a couple of years ago, but now lags some competitors noticeably at the upper end. The ISO sensitivity is adjusted in Program, Priority, and Manual modes by pressing the dedicated ISO button on the A77's top panel, or through the ISO option in the Function menu, and adjustments can be made in third-stop increments.

In Program and Priority modes, but not in Manual mode, an Auto ISO mode is available, and in Auto, Auto+, Scene, and Sweep Panorama modes, it's the only option. The upper and lower limits for the function can be manually set within a range of ISO 100 to 12,800 in all modes except Movie (which has an upper limit of ISO 1,600), and those that require Auto ISO (which leave the range in the camera's control).

In addition, the Sony A77 offers a Multi-Frame NR function, which combines multiple shots into a single output image, in a similar manner to the Hand-held Twilight scene mode. The difference between the two functions is that Multi-Frame NR allows direct control over ISO sensitivity. Multi-Frame NR is available only in the Program, Priority, and Manual modes, and is accessed from the ISO sensitivity dialog. When using Multi-Frame NR, the maximum ISO sensitivity limit is expanded to ISO 25,600 equivalent.

Sony A77 Noise Reduction
The Sony A77 gives you only three choices for High ISO noise reduction, none of which allows the function to be completely disabled. The default is to leave High ISO NR entirely in the camera's control, but if the maximum image detail is desired (or you prefer to do your noise filtering in post processing), a "Low" option is also available in Program, Priority, and Manual modes. There's also a "High" option if you don't want to post-process and prefer lower noise levels.

A separate Long Shutter noise reduction On / Off setting is available in Program, Priority, and Manual modes, for dark frame subtraction when shooting exposures of one second or longer. If enabled, this approximately doubles the exposure time for each shot, allowing the second dark frame exposure to be captured with the shutter closed.

Sony A77 White Balance Options
White balance modes on the Sony A77 include Auto, Daylight, Shade, Cloudy, Incandescent, Fluorescent (Warm White, Cool White, Day White, or Daylight), and Flash. A direct Kelvin temperature setting is also available, ranging from 2,500K to 9,900K, as are three Custom white balance settings, for setting white balance from a white or grey card. The A77's popup flash strobe can be used when determining a custom white balance, and unusually, the camera also provides a Kelvin readout of the measured color temperature -- a great feature which lets you subsequently dial the temperature in directly if you're shooting in familiar conditions. The effect of changes in white balance settings is shown in real-time on the LCD monitor and EVF.

In all of the preset white balance modes, you can fine-tune the color by pressing the left / right arrow keys on the four-way controller while in the White Balance menu. Blue / red adjustment is possible within a range of -3 to +3 arbitrary units for all but the fluorescent mode, which offers only a -1 to +2 unit range. In Kelvin white balance mode, there's also a color filter function which offers a magenta - green filter within a fairly wide range of -9 to +9 arbitrary units.

Custom white balance is set by selecting Custom Setup from the white balance menu, and pointing the camera at a neutral white or grey card under the lighting you'll be shooting in, filling a frame in the center of the display with the reference target, then pressing the Shutter button.

In addition, the Sony A77 can bracket white balance using the White Balance Bracketing (BRK WB) option in the Drive Mode menu. For each shutter release, the A77 records three separate image files, varying only the white balance between each image. Two step sizes are available -- 10 mireds when using the BRK WB Lo setting, and 20 mired steps with the BRK WB Hi setting.

Sony A77 Metering Options
The Sony Alpha A77 offers three metering modes, selected via the Metering Mode option in the Function menu: Multi-segment, Center-weighted, and Spot. All three modes operate on data from the camera's CMOS image sensor. The default Multi-segment metering mode divides the image into a very fine-grained 1,200 segments. Center-Weighted gives precedence to the center of the image while reading the whole frame. Spot metering is useful for high-contrast subjects, as it bases the exposure reading on the very center of the image, letting you set the exposure based on a small portion of your subject. When the camera is operating in Auto, Auto+, or Scene modes, the metering mode is fixed to Multi-pattern, and cannot be changed.

By default, you can lock an exposure reading separately from autofocus lock by pressing and holding the AEL button. Alternatively, the AEL button behaviour can be changed so that pressing and releasing the button will set and release the autoexposure lock on subsequent presses.

Sony A77 Exposure Compensation & Bracketing
The Sony A77's Exposure Compensation adjustment increases or reduces the overall exposure from -5 to +5 exposure values (EV) in one-third stop increments, and like White Balance, the effect of Exposure Compensation is simulated on the preview image if possible. In addition, the A77 offers -3 to +3 EV of flash exposure compensation, in 1/3 EV increments, set through the Function menu. A Continuous Bracketing feature captures multiple shots with different exposures. See the Drive Mode section on Continuous Bracketing below for more details.

Sony A77 DRO / HDR
The Sony A77 offers two different functions aimed at handling high-contrast scenes, each functioning in a rather different manner. The Dynamic Range Optimization (DRO) function adjusts the tone curve of captured images, bringing out shadow detail without adversely affecting highlights. As well as an Auto DRO mode, there are also five different levels of DRO available. Alternatively, Sony has included a high dynamic range (HDR) mode, which captures three separate images with varied exposures, and then combines the images in-camera, creating a single image with significantly increased dynamic range. The A77 can either automatically select the exposure variation, or a value can be selected manually in 1EV steps within a range of 1EV to 6EV.

The DRO and HDR modes can't be used together, and each brings its own set of advantages and disadvantages. Since DRO only works from a single shot, it must operate entirely within the dynamic range available from the image sensor, where the HDR mode is able to capture a significantly greater dynamic range than is possible in one shot. Since DRO is effectively amplifying the signal in shadow areas of the image, it also brings increased noise (or increased noise reduction) in the shadows. HDR mode, meanwhile, is suitable only for relatively static subjects, given that it requires multiple exposures. Thanks to microalignment capability, Sony's HDR mode is at least able to deal with the slight changes in framing caused by shooting handheld, but subject motion or camera shake will likely cause unacceptable artifacts in HDR images.

Both DRO and HDR can be disabled altogether if desired, although the default on the A77 is for DRO Auto mode to be left enabled.

Sony A77 Hand-held Twilight
Another function which the Sony A77 has inherited from the company's point-and-shoot camera line is its Hand-held Twilight mode, which is accessed from the Scene (SCN) position on the Mode dial. Hand-held Twilight mode shoots a burst of six images with a single press of the shutter button, using as high sensitivity as is necessary to offer hand-holdable shutter speeds. The A77 then combines all six source images into one image with reduced noise in static areas, as compared to a single shot taken with the same exposure settings. Cleverly, Hand-held Twilight mode is able to deal with moving subjects, by making the assumption that the first frame includes your intended subject. Areas of subsequent images which match up with the first image are factored into the final result, but areas that don't match -- either due to subject or camera motion -- aren't used in creating the final image. This does, however, mean that the moving subject doesn't benefit from the same degree of noise reduction as the rest of the image.

The Sony A77's implementation of Hand-held Twilight does have one important difference from the similar mode found on its point-and-shoot siblings. Where the existing cameras have been able to use an electronic shutter to capture the source images, the A77 must instead rely on its physical shutter. The A77's mirror slap isn't the quietest we've heard, and with six frames captured in a rapid burst, its Hand-held Twilight mode can have bystanders turning around in expectation of seeing a paparazzo in their midst. ;-)

Sony A77 Sweep Panorama
The final mode inherited from Sony's Cyber-shot point-and-shoot lineup is the A77's Sweep Panorama function, with which it can automatically capture a burst of images, and stitch them into a single panoramic image in-camera. Both 2D and 3D modes are offered, with the latter cleverly comparing the relative positions of subjects as they pass the left and right sides of the lens, and using this information to create a 3D image consisting of separate 2D views, stored in a Multi Picture Object file.

Again, since there's no electronic shutter to rely on, the mirror slap noise means you won't be catching anybody by surprise, That said, the feature functions pretty well if you've a reasonably steady hand, and your subject matter isn't too close to the camera. If your subject matter is too close to the camera, or your panning isn't smooth and straight, the seams between separate images can become fairly noticeable. Focus and exposure are locked from the first frame of the panorama, so you'll want to pick your starting point carefully. From there, you can pan left, right, up, or down, simply sweeping the camera across your subject matter after pressing the shutter button.

Two panorama sizes are available -- standard, or wide. Standard horizontal panoramas are limited to 15 megapixels, and vertical panoramas to 8.4 megapixels. In Wide mode, horizontal panoramas are 23 megapixels, and vertical panoramas are 12 megapixels. For 3D mode, only horizontal panoramas are possible, with the standard size providing 5.3 megapixel resolution, and the wide size offering 7.7 megapixels. There's also a 1,920 x 1,080 pixel mode designed to match the resolution of a Full HD display, available only for 3D panoramas.

A darkened mask over the left third of the LCD display shows an area of the frame that won't be included in the final output image, and an on-screen message warns you if the Alpha A77 wasn't able to track your panning, prompting you to recapture the panorama. (Depending on how much was captured, the A77 sometimes retains a partial panorama with the uncaptured portion of the image left as a flat grey.)

Sony A77 Drive Modes
The Sony A77 offers a variety of shooting modes, accessed via a dedicated Drive Mode button on the camera's top deck, or through the Drive Mode option under the Function menu. Options vary depending on the shooting mode, but include Single Shot Advance, two Continuous Advance modes, two Self Timer modes, Continuous Bracket, Single Bracket, White Balance Bracket, DRO Bracket, and Remote Commander. Single-shot, as you'd expect, captures a single image with each press of the shutter button. Continuous Advance captures images at either eight frames per second in Hi mode, or three frames per second in Lo mode, while the shutter button is held down. As many as 13-15 shots can be captured in a burst depending upon file type, adjusting focus and exposure between shots as necessary.

The Self-timer modes offers a choice of either two or ten second timers. The Bracket modes let you take a sequence of three or five shots with either 0.3, 0.5, or 0.7 EV exposure variation steps, or three shots with 2.0 or 3.0 EV steps. The sequence order is to shoot the metered exposure first, followed by the underexposed and overexposed frames. The difference between the two modes is that Continuous Bracket will capture all the necessary frames as fast as possible while the shutter button is held down, while Single Bracket requires you to full press the shutter button once per frame. White Balance Bracket captures three images with varied white balance settings, as described in the white balance section of this page. DRO Bracket offers two choices: Low captures three images at DRO levels 1 to 3, and High at levels 1, 3, and 5. Finally, Remote Commander mode configures the A77 to capture images as directed by the optional RMT-DSLR1 wireless remote control, which communicates with the camera via an infrared receiver hidden behind a shiny plastic trim piece in the top of the hand grip's front surface.

Finally, Continuous Advance Priority AE mode is accessed via a dedicated Mode dial position, and locks the lens aperture at either F3.5 or the maximum aperture of the lens, whichever is smaller, removing the delay required to set and reset the aperture to allow focusing between shots. This enables the camera's fastest burst-shooting performance of 11.6 frames per second, according to our in-house testing. 

Sony A77 Creative Styles
Finally, the Creative Style option on the Function menu allows photographers to set the A77's color mode. Six preset options are available -- Standard, Vivid, Neutral, Portrait, Landscape, and B/W. For all six choices, Contrast and Sharpness levels may be adjusted in seven steps. In addition, all but the black and white mode offer seven-step control over saturation. A separate Color Space option under Screen 3 of the Record menu lets you choose between sRGB and AdobeRGB color spaces, with sRGB being best for viewing images on a computer, and Adobe RGB the best choice for printing images.

Sony A77 Geotagging
Finally, the Sony A77 allows geotagging of images and movies at the time of capture. This allows them to be tagged with information regarding capture location, including latitude, longitude, altitude, receiver speed and direction, and the GPS time stamp. Movies are only tagged with information regarding the location at the start of the clip. Accuracy will vary depending on the number of satellites in view at a particular time and location. The initial GPS lock can take several minutes to achieve, if the camera hasn't been used recently, although again this can depend on environmental conditions, as well as the number and position of satellites in view. It's possible to reduce this time by uploading GPS-assist data to the A77 body using Sony's provided Picture Motion Browser software, which can greatly reduce the length of time required to obtain a GPS lock. This process has to be repeated roughly once per month, as the assist data is only good for so long. You can also set the A77 to automatically update its clock based on the time provided by GPS satellites.

The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Sony Alpha SLT-A77 Photo Gallery .

Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Sony Alpha SLT-A77 with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!

Performance

Note: The following performance data has been updated after upgrading to v1.06 firmware.

Imaging

Color

Saturation & Hue Accuracy
Slightly bright colors at lower ISOs, with good hue accuracy.

ISO Sensitivity
50	100	200	400	800
1600	3200	6400	12800	16000
In the diagram above, the squares show the original color, and the circles show the color that the camera captured. More saturated colors are located toward the periphery of the graph. Hue changes as you travel around the center. Thus, hue-accurate, highly saturated colors appear as lines radiating from the center. Mouse over the links to see results across the ISO range, and click on the links for larger images.

Saturation. Like many cameras, the Sony A77 pushes strong reds, dark blues and some oranges, greens, purples and browns just a little, but undersaturates yellow, aqua and cyan tones slightly. The A77's mean color saturation of 111.9% (11.9% oversaturated) at base ISO is just a touch higher than average for a professional SLR, though the camera allows you to tweak saturation to your liking, or choose a different color mode. Saturation remained fairly consistent up to ISO 1,600, but dropped off at higher ISOs. Most consumer digital cameras produce color that's more highly saturated (more intense) than found in the original subjects. This is simply because most people like their color a bit brighter than life.

Skin tones. Here, when adjusted for the correct white balance, the Sony A77 did well, producing natural-looking lighter Caucasian skin tones, though darker skin tones show a slight push toward orange. Where oversaturation is most problematic is on Caucasian skin tones, as it's very easy for these "memory colors" to be seen as too bright, too pink, too yellow, etc.

Hue. The Sony A77 did push cyan toward blue, red toward orange, orange toward yellow and yellow toward green, but shifts were relatively minor. (The cyan to blue shift is very common among the digital cameras we test; we think it's a deliberate choice by camera engineers to produce better-looking sky colors.) With an average "delta-C" color error of 5.31 after correction for saturation, overall hue accuracy was slightly lower than average for a professional SLR at base ISO these days, but still pretty good. Hue accuracy was fairly stable across the ISO range. Hue is "what color" the color is.

Creative Style
The Sony A77 offers up to 13 preset "Creative Style" options depending on the firmware version. You can adjust contrast, saturation (except for B&W and Sepia), and sharpness for any of the settings. Below are eight of them. Not shown: Deep, Light, Sunset, Autumn Leaves and Sepia.

Creative Style Options
Standard (default)	B&W	Clear
Landscape	Neutral	Night Scene
Portrait	Vivid

Mouse over the links above to see the effect of the presets on our Still Life target. Click on a link to load the full resolution image.

Saturation Adjustment
The Sony A77 has a total of seven saturation settings available, three above and three below the default saturation. The fine steps between settings mean you can program the camera to just the level of saturation you prefer, a feature we look for in cameras. Saturation also had little effect on contrast, which is ideal.

Saturation Adjustment Examples
-3	-1	0	+1	+3

The table above shows results with the seven saturation settings. Click on any thumbnail above, then click again to see the full-sized image.

Sensor

Exposure and White Balance

Indoors, incandescent lighting
Very warm cast with the Auto white balance setting and slightly warm with Incandescent, but good color with the Manual setting. Slightly above average positive exposure compensation required.

Indoors, under normal incandescent lighting, color balance was overly warm and orange with the Auto white balance setting and quite disappointing. Results with the Incandescent setting were good, though, just slightly warm and yellow. The Manual setting was very accurate, but some may prefer Incandescent because it conveys a touch more of the warmth of the original lighting. The 2,600 Kelvin setting which matches the color temperature of our lights resulted in a slightly cool, bluish image. The Sony A77 required +0.7 EV positive exposure compensation here, which is slightly above the average of +0.3 EV usually needed for this shot. (Our test lighting for this shot is a mixture of 60 and 100 watt household incandescent bulbs, a pretty yellow light source, but a very common one in typical home settings here in the U.S.)

Outdoors, daylight
Excellent results under harsh lighting, with good handling of contrast, color, and exposure.

Outdoors, the Sony A77 performed very well. +0.3 EV exposure compensation was required to keep the mannequin's face bright in our "Sunlit" Portrait shot. The average among the cameras we've tested is +0.7 EV, so the A77 performed better than average here. Contrast is somewhat high, as you might expect under such harsh lighting, but the camera does an excellent job of holding onto detail in both the deep shadows and bright highlights. Despite the bright appearance, relatively few highlights were clipped even without the help of Dynamic Range Optimization (DRO was off for these shots). Color balance was quite good, though Auto white balance rendered the model's face a touch warm, so we preferred Manual white balance here. Default exposure was quite good for our Far-field shot as well, again with excellent highlight retention, though some shadows were quite dark and plugged. The Far-field shot using Auto white balance had good color. Overall, very good performance in harsh lighting.

See full set of test images with explanations
See thumbnails of all test and gallery images

Resolution
Very high resolution, about 2,750 to 2,850 lines of strong detail in camera JPEGs, a bit higher from RAW.

In camera JPEGs of our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,850 lines per picture height in the horizontal direction, and about 2,750 in the vertical direction (some might argue for over 2,800 lines, but aliasing artifacts begin to interfere before then), with extinction of the pattern occurring between 3,400 and 3,600 lines. We were only able to extract about 50 lines per pixel height more from the RAW file using Adobe Camera Raw 6.7b. Use these numbers to compare with other cameras of similar resolution, or use them to see just what higher resolution can mean in terms of potential detail.

See full set of test images with explanations
See thumbnails of all test and gallery images

Sharpness & Detail
Sharp images with very good detail, but some edge-enhancement artifacts are visible on high-contrast subjects. Low to moderate noise suppression visible in the shadows and areas of low contrast.

Sharpness. The Sony A77 captures sharp images with very good detail overall, though fine detail is somewhat soft at default settings even at base ISO, despite fairly obvious sharpening halos visible around high-contrast subjects such as the larger branches and pine cones in the crop above left (which was shot with a very sharp Carl Zeiss 24-70mm f/2.8 SSM lens at f/8). Fine detail such as the smaller branches and pine needles show minimal edge enhancement, but appear a touch soft and feathery. Remember, though, that we're looking at a 24-megapixel image on screen at 100%, so results here are pretty good. See the bottom of this page for our analysis of printed results. Edge enhancement creates the illusion of sharpness by enhancing colors and tones right at the edge of a rapid transition in color or tone.

Detail. The crop above right shows low to moderate noise suppression in the darkest areas of the model's hair. Some individual strands are smudged together, though quite a few strands are still visible despite the low contrast subject. We saw similar results with fine detail in the pine needles. Still, pretty good results here especially considering the resolution. Noise-suppression systems in digital cameras tend to flatten-out detail in areas of subtle contrast. The effects can often be seen in shots of human hair, where the individual strands are lost and an almost "watercolor" look appears.

RAW vs In-Camera JPEGs
As noted above, the Sony A77 produces sharp in-camera JPEGs, though fine detail is a touch soft and sharpening halos are visible around high-contrast elements. Better detail with fewer sharpening artifacts can often be obtained from carefully processing RAW files with a good RAW converter.

In-camera Extra Fine JPEG, (Defaults)	RAW via Sony IDC (Defaults)	RAW via ACR (Sharpened)

In the table above, mousing over a link at the bottom will load the corresponding crop in the area above, and clicking on the link will load the full resolution image. Examples include (from left to right): an in-camera Extra Fine JPEG, RAW file processed through Sony's Image Data Converter SR version 4.0 software at default settings, and the same ARW file converted with Adobe Camera Raw 6.7b and sharpened with unsharp make of 150% and radius 0.6 in Photoshop.

Sony's IDC 4.0 software produces images similar to in-camera JPEGs, though exposure is a bit lower, and fine detail a bit softer than the camera's default JPEG processing. We weren't able to extract much more detail by fiddling with IDC's noise reduction and sharpening settings. The Adobe Camera Raw conversion shows improved detail, with better definition of fine detail while at the same time producing less sharpening halos, though noise is a little more visible in flat areas such as the sky. You can always tweak noise reduction and sharpening to your liking after capture, though, one of the advantages of shooting RAW.

ISO & Noise Performance
Very good noise versus detail performance up to ISO 800, though somewhat strong default noise reduction at higher ISOs.

Default High ISO Noise Reduction
ISO 50	ISO 100	ISO 200
ISO 400	ISO 800	ISO 1,600
ISO 3,200	ISO 6,400	ISO 12,800
ISO 16,000

The Sony A77's images are quite clean and detailed at ISO 50 through 200, and even ISO 400 looks quite good. Some noise "grain" is noticeable at ISO 800, as well as a small amount of smudging in lower contrast areas, but the camera did a good job of holding on to fine detail here. There's some stronger smudging of fine detail at ISO 1,600, but detail remains good. At ISO 3,200, fine detail suffers from higher luminance noise and more aggressive noise reduction, though some detail remains. Chroma noise starts to become more noticeable at ISO 3,200 as well, but it's not too bad. As you might expect, fine detail disintegrates at ISO 6,400 and especially at 12,800 and 16,000, where chroma noise also becomes much more noticeable and images have a strong stippled effect. Saturation falls off at the highest ISOs as well. Overall though, these are good results for the resolution, though not quite as good as the Sony NEX-7 which also uses a similar if not identical 24-megapixel CMOS sensor. We speculate that the loss of light through the SLT mirror is putting the A77 at a disadvantage over the mirrorless NEX-7. As always, see the Print Quality section below for maximum recommended print sizes at each ISO.

A note about focus for this shot: We shoot this image at f/4, usually using one of three very sharp reference lenses (70mm Sigma f/2.8 macro for most cameras, 60mm f/2.8 Nikkor macro for Nikon bodies without a drive motor, and Olympus Zuiko 50mm f/2.0 for Four Thirds and Micro Four Thirds bodies). To insure that the hair detail we use for making critical judgements about camera noise processing and detail rendering is in sharp focus at the relatively wide aperture we're shooting at, the focus target at the center of the scene is on a movable stand. This lets us compensate for front- or back-focus by different camera bodies, even those that lack micro-focus adjustments. This does mean, though, that the focus target itself may appear soft or slightly out of focus for bodies that front- or back-focused with the reference lens. We know this; if you click to view the full-size image for one of these shots and notice that the focus target is fuzzy, you don't need to email and tell us. :-) The focus target position will have been adjusted to insure that the rest of the scene is focused properly.

Extremes: Sunlit, dynamic range and low light tests
Very high resolution with good dynamic range. Very good low-light performance, capable of capturing bright images in near darkness.

Sunlight. The Sony A77 handled the deliberately harsh lighting in the test above very well. We preferred the +0.3 EV exposure here, as the mannequin's face was a little dark at default exposure. Contrast is a little high, but highlight detail is actually very good. Despite the apparent brightness, there are very few clipped highlights in the model's face and shirt. There were some pretty deep shadows though, and noise is a little high in the shadows but a lot of fine detail is intact. Overall, pretty good results here. Still, be sure to use fill flash in situations like the one shown above; it's better to shoot in the shade when possible. See below for results with Dynamic Range Optimization and High Dynamic Range features enabled.

Because digital cameras are more like slide film than negative film (in that they tend to have a more limited tonal range), we test them in the harshest situations to see how they handle scenes with bright highlights and dark shadows, as well as what kind of sensitivity they have in low light. The shot above is designed to mimic the very harsh, contrasty effect of direct noonday sunlight, a very tough challenge for most digital cameras. (You can read details of this test here. In actual shooting conditions, be sure to use fill flash in situations like the one shown here; it's better to shoot in open shade whenever possible.)

Dynamic Range Analysis
A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)

What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work.

JPEG. The graph at right (click for a larger version) was generated using Imatest's dynamic range analysis for an in-camera Sony A77 JPEG file with a nominally-exposed density step target (Stouffer 4110). At the base ISO of 100 (the optimal ISO in our tests) with DRO and HDR settings turned off, the graph shows 11.7 f-stops of total dynamic range, 7.48 f-stops at the "High" Quality level, and fairly gradual roll-offs at both the highlight and shadow ends of the tone curve. These are are very good results, especially total dynamic range, though not quite as good as the best APS-C sensors to date. The 7.48 f-stops at the High Quality level is a function of the slightly higher than average noise, a natural result of the higher pixel density compared to 16-megapixel APS-C models. Note though that this measurement has a margin of error of about 1/3 f-stop, so differences of less than 0.33 can be ignored when comparing to other models.

RAW. The graph at right is from the same Stouffer 4110 stepchart image captured as a RAW (.ARW) file, processed with Adobe Camera Raw using the Auto setting. (Slightly better results are likely possible with manually tweaking, but we weren't able to do much better.) As can be seen, the score at the highest quality level increased from 7.48 to 9.35 f-stops, which is almost a two f-stop improvement, while total dynamic range increased 1.6 f-stops, to 13.3 from 11.7. The High Quality results are very good, though again not quite as good as the best APS-C sensors we've tested, hampered somewhat by slightly higher noise levels from the A77's denser sensor. (The Nikon D7000 for example scored 10.1 f-stops at the highest quality level, while the Pentax K-5 scored 10.2 f-stops.) It's also worth noting here is that ACR's default noise reduction settings reduced overall noise somewhat (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the higher quality thresholds. Total dynamic range however is excellent, one of the highest scores we've recorded to date.

Contrast Adjustment
We really like it when a camera gives us the ability to adjust contrast and saturation to our liking. It's even better when those adjustments cover a useful range, in steps small enough to allow for precise tweaks. Just as with its saturation adjustment, the Sony A77's contrast setting meets both challenges.

Minimum Contrast
Contrast set to lowest, 0 EV	Contrast set to lowest, 0 EV

At its lowest contrast setting, the A77 did a really nice job of opening up shadow detail while maintaining natural-looking skin tones. Overall, very good results here. (This is a really tough shot; the Sony does a much better than average job handling it.)

Contrast Adjustment Examples
-3	-1	0	+1	+3

The table above shows five of the seven contrast settings, including the default and two extremes. It's pretty hard to evaluate small differences in contrast on small thumbnails like these, so click on any thumbnail to go to the full-size image.

Sony's contrast adjustment has very little effect on color saturation, which is always a plus. Contrast and saturation are actually fairly closely coupled, so it's a good trick to be able to vary one with out the other changing as well.

Outdoor Portrait DRO Comparison
	DRO Setting: Auto (Default) Off Level 1 Level 2 Level 3 Level 4 Level 5

Dynamic Range Optimization is Sony's name for their dynamic range enhancement technology. DRO divides the image into small areas, analyzes the range of brightness of each area, and adjusts the camera's image processing parameters accordingly to make the best use of the available dynamic range. Auto DRO is enabled by default on the Sony A77. You can also set the level manually, from 1 ("weak") to 5 ("strong"), or turn it off. As one would expect, DRO is only available for JPEG files.

The above thumbnails and histograms show the effects of the various levels of DRO on our "Sunlit" Portrait shot with no exposure compensation. Mouse over the links to load the associated thumbnail and histogram, and click on the links to visit the full resolution image. As you can see from the thumbnails and associated histograms, DRO had only a slight effect on the highlights in this shot, though few highlights were clipped to begin with. The bulk of the difference between different levels of DRO is found in the shadows and darker midtones. The stronger the DRO level, the more boost is applied to darker areas. Boosting shadows does reveal more visible noise, but the A77 does a good job at holding on to detail in the shadows, as opposed to blurring it away with strong noise reduction. The default Auto DRO setting did a pretty good job here.

Far-field DRO Comparison
Auto (default)	Off	Level 1	Level 2
Level 3	Level 4	Level 5

Above, you can see the effect of DRO settings on our Far-field shot. The default Auto setting produced a good exposure overall, despite the harsh lighting.

Outdoor Portrait HDR Comparison
	HDR Setting: Off (Default) Auto 1 EV 2 EV 3 EV 4 EV 5 EV 6 EV

High Dynamic Range. The Sony A77's HDR mode takes three images in rapid succession, one nominally exposed, one underexposed, and one overexposed, then combines them into one high dynamic range JPEG automatically. Lighter areas from the underexposed image are combined in-camera with darker areas from the overexposed image to produce an image with increased dynamic range. The camera then saves a single composite image, as well as the nominally exposed image. The overlaid images are micro-aligned by the camera, but it can only correct for so much movement. If it can't micro-align successfully, an icon indicating HDR capture failed will appear. For best results, the subject should not move or blink, so it's not really intended for portraits. There is also a manual mode where you can select 1 EV ("weak") to 6 EV ("strong") difference in exposures.

Mouse over the links to load the associated thumbnail and histogram, and click on the links to visit the full resolution image. As you can see, the highest settings produce images that looked flat and unnatural with this scene, however Auto and the lower manual settings did a pretty good job at boosting shadows. reducing highlights, while still retaining enough contrast.

Far-field HDR Comparison
Off	Auto	1 EV	2 EV
3 EV	4 EV	5 EV	6 EV

Above, you can see the effect of HDR settings on our Far-field shot. As mentioned above, merging multiple images to generate a composite HDR image is really meant for completely static images. Here, you can see some ghosting in the flag and leaves, caused by motion between the captures, so watch out for that when using this feature.

	1 fc 11 lux	1/2 fc 5.5 lux	1/4 fc 2.7 lux	1/8 fc 1.3 lux	1/16 fc 0.67 lux	1/16fc No NR	1/16fc MFNR
ISO 50	3.2 s f2.8	6 s f2.8	13 s f2.8	25 s f2.8	30 s f2.8	30 s f2.8	n/s
ISO 100	1.6 s f2.8	3.2 s f2.8	6 s f2.8	13 s f2.8	25 s f2.8	25 s f2.8	25 s f2.8
ISO 200	0.8 s f2.8	1.6 s f2.8	3.2 s f2.8	6 s f2.8	13 s f2.8	13 s f2.8	13 s f2.8
ISO 400	0.4 s f2.8	0.8 s f2.8	1.6 s f2.8	3.2 s f2.8	6 s f2.8	6 s f2.8	6 s f2.8
ISO 800	1/5 s f2.8	0.4 s f2.8	0.8 s f2.8	1.6 s f2.8	3.2 s f2.8	3.2 s f2.8	3.2 s f2.8
ISO 1600	1/10 s f2.8	1/5 s f2.8	0.4 s f2.8	0.8 s f2.8	1.6 s f2.8	1.6 s f2.8	1.6 s f2.8
ISO 3200	1/20 s f2.8	1/10 s f2.8	1/5 s f2.8	0.4 s f2.8	0.8 s f2.8	0.8 s f2.8	0.8 s f2.8
ISO 6400	1/40 s f2.8	1/20 s f2.8	1/10 s f2.8	1/5 s f2.8	0.4 s f2.8	0.4 s f2.8	0.4 s f2.8
ISO 12800	1/80 s f2.8	1/40 s f2.8	1/20 s f2.8	1/10 s f2.8	1/5 s f2.8	1/5 s f2.8	1/5 s f2.8
ISO 16000	1/100 s f2.8	1/50 s f2.8	1/25 s f2.8	1/13 s f2.8	1/6 s f2.8	1/6 s f2.8	n/s
ISO 25600	n/a	n/a	n/a	n/a	n/a	n/a	1/10 s f2.8

Low Light. The Sony A77 performed well in our low light test, producing bright images down to the lowest light level we test at (1/16 foot-candle) at all ISO settings, though ISO 50 is a bit dim at the lowest light levels because of the 30 second limit in shutter speed (there is a bulb mode for longer exposures). The A77's metering system struggled a bit at very low light levels though, so we used manual exposure for these shots as we often need to do. Noise is well controlled up to ISO 1600, though as expected, at higher ISOs there are moderate to high amounts of fine luminance noise and some blotchy chroma noise. Auto white balance did a good job here, producing a slightly cool color balance at most ISOs and light levels, though it occasionally produced a warmer white balance. There are a few bright pixels at higher ISOs and lower light levels, and some minor horizontal banding is visible at very high ISOs, but that's not uncommon. Some heat blooming emanating from the bottom right corner is also visible at highest ISOs, especially with long exposure noise reduction turned off, but again, that's normal at extreme ISOs.

We've also included low light shots taken with the Sony A77's Multi-frame Noise Reduction feature here at the lowest light level (extreme right column). As you can see, MFNR really makes quite a difference in noise levels (see below for more). Note that Multi-frame Noise Reduction is not supported at ISO 50 or 16,000.

The camera's autofocus system was able to focus on the subject down to just below the 1/8 foot-candle light level unassisted with the DT 16-50mm f/2.8 lens, and in complete darkness with AF assist enabled. This is good performance, but some SLRs are able to autofocus to below 1/16 foot-candle without AF assist.

How bright is this? The one foot-candle light level that this test begins at roughly corresponds to the brightness of typical city street-lighting at night. Cameras performing well at that level should be able to snap good-looking photos of street-lit scenes.

NOTE: This low light test is conducted with a stationary subject, and the camera mounted on a sturdy tripod. Most digital cameras will fail miserably when faced with a moving subject in dim lighting. (For example, a child's ballet recital or a holiday pageant in a gymnasium.) Thanks to their phase-detect AF systems, digital SLRs like the Sony A77 tend to do much better than point & shoots, but you still shouldn't expect a quick autofocus lock with moving subjects. (A useful trick is to just prop the camera on a convenient surface, and use its self-timer to release the shutter. This avoids any jiggling from your finger pressing the shutter button, and can work quite well when you don't have a tripod handy.)

Low Light Multi-frame NR
Default NR, 1/5s, ISO 12,800	Multi-frame NR, 1/5s, ISO 12,800

Multi-frame Noise Reduction. This feature is similar to Sony's Hand-held Twilight mode which shoots a burst of six images with a single press of the shutter button and combines all six images into one composite image with reduced noise. But unlike Hand-held Twilight, Multi-frame NR gives you control over the ISO, aperture and shutter speed used, so you may still need to use a tripod depending on the exposure parameters you select. (We frankly don't see the value to this mode when using a tripod, as selecting a lower ISO and longer shutter speed will produce a cleaner image as well.) As you can see, the image captured with Multi-frame Noise Reduction (right) is cleaner than the standard image (left) despite both being shot at ISO 12,800. An added bonus is that ISO 25,600 equivalent is available with MF NR.

Output Quality

Print Quality

100% crops onscreen can only tell you so much, especially when comparing cameras of different resolutions. So we always print samples of various sizes to determine the maximum print size at each ISO setting. To avoid printing massive stacks, we print only JPEGs generated from our test images taken at default noise suppression settings. Usually you can get quite a bit more processing the images from RAW.

Note: This is an updated print quality analysis based on images printed with the firmware version installed when the production-level lab shots were taken (v1.03), revealing a slight increase in overall quality from the pre-production version (v0.58) .

ISO 50/100 prints look quite good at 30 x 40 and terrific at 24 x 36.

ISO 200 prints are again excellent at 24 x 36 inches.

ISO 400 prints are also good at 24 x 36 inches.

ISO 800 shots print quite well at 20 x 30 inches.

ISO 1,600 shots look great at 16 x 20, although hints of noise appear in light shadows.

ISO 3,200 makes a nice 11 x 14 inch print, although there is some large, diffuse chroma noise in areas of flat tints.

ISO 6,400 images are usable at 8 x 10, if a little rough in some spots. We prefer the 5 x 7 images.

ISO 12,800 and 16,000 do not produce usable prints and are best avoided.

Overall, the Sony A77's image quality is excellent. Once we installed the updated firmware and reshot and printed the updated images, we were able to give slightly higher recommendations at several ISO settings than we were able to give with the prototype, based mainly on the update's ability to more accurately render data in the red channel.

Testing hundreds of digital cameras, we've found that you can only tell just so much about a camera's image quality by viewing its images on-screen. Ultimately, there's no substitute for printing a lot of images and examining them closely. For this reason, we now routinely print sample images from the cameras we test on our Canon Pro9000 Mark II studio printer, and the Canon Pixma MP610 here in the office. (See the Canon Pixma Pro9000 Mark II review for details on that model.)

Video

Sony A77 Video Recording

Video capability. Although there is a separate video recording mode on the Sony A77, capture can still be initiated from any still-image mode by pressing the Movie button at top rear of the body.

High-definition video capture is now a must-have feature in interchangeable-lens cameras, and essentially all the major manufacturers now provide some form of video capture in their compact system cameras. Sony's Translucent Mirror cameras offer a near-unique capability in this area: the ability to focus automatically using phase detection. With the exception of Nikon's 1-series cameras, all other interchangeable-lens models must focus solely using contrast detection. Post Sony SLT cameras have tempered this benefit somewhat, by lacking other features such as fully manual exposure control, but the Sony A77 has a pretty rich video feature set in other areas as well. Full HD is possible, and at an impressive 60 frames per second from real 60 fps sensor data. There's also a generous selection of frame rates available, at least at the highest resolution. Fully manual exposure control is available, both before and during recording, but there's a catch: all except Program autoexposure disable autofocus entirely, losing the main benefit of an SLT design for video, and you don't even have contrast-detect AF to fall back upon. On the plus side, though, you have both stereo audio from the internal microphone and from an external mic jack, and while the A77 doesn't offer manual audio levels control, there's a wind cut filter available.

For its target customer, the few quirks are likely not of great importance, however. If you want to control exposure variables manually, you'll likely also want to lock focus or pull it manually, as well. A simple external audio recorder and a few minutes in post-processing would be enough to surmount the lack of manual levels control, if that's an issue. On balance, we think the feature set will prove pretty attractive even to many prosumers.

Let's look at the Sony A77's video capabilities in a bit more detail:

Sony A77 Basic Video Specs

• 1080p / 1080i (1,920 x 1,080) high definition video at either 59.94p or 23.976p (progressive-scan) frames/second, or 59.94i (interlaced) fields / second (50p/i and 25p for European versions)
• 28 Mbps recording at 1080p60, choice of 24Mbps or 17 Mbps for other 1080 video modes; 59.94p mode is derived from real 60fps sensor data, not frame-doubled from 30fps (!)
• HDV 1080i (1,440 x 1,080 rectangular pixels), 29.97 fps, 12 Mbps, HD recording (25 fps in European versions) in MPEG-4 format
• VGA (640 x 480), 29.97 fps, 3Mbps standard-definition recording (25 fps in European versions) in MPEG-4 format
• 1,920 x 1,080 video is AVCHD compression (MPEG-4 AVC / H.264 w/ Dolby Digital audio) in a .MTS container; lower resolutions are MPEG-4 with AAC-LC audio in .MP4 container
• Maximum clip length is 29 minutes; MPEG-4 video also stops after 2GB, but AVCHD spans new files every 2GB
• Full-time phase-detect autofocus with tracking during video capture (!)
• Automatic, priority, or manual exposure modes, but autofocus is only available with autoexposure, and exposure changes don't step smoothly
• Shutter, aperture, ISO, exposure compensation available, AF lock, AF area, and tracking can be set both before and during movie capture
• Maximum ISO sensitivity limited to 1,600 equiv. for video capture
• SteadyShot image stabilization, white balance, creative style, some picture effects, metering mode, DRO, and lens corrections can be set before movie capture begins
• Stereo audio recording via built-in microphones on top deck, or via a standard 3.5mm external mic jack
• Audio recording can be disabled altogether, and wind cut filter is available
• Video is cropped significantly from sensor data, making wide-angle video harder to achieve; optional crop marks can be shown in EVF or on LCD if not in movie mode
  
  

Sony A77 Video: Image Size, Frame Rate, and Encoding

The Sony A77 records at three different video resolutions, and can record high-definition movies in either AVCHD or MPEG-4 formats. Stereo audio is recorded during movie capture, encoded as Dolby Digital (AC-3) for AVCHD and AAC-LC for MPEG-4. No spec is provided for the sampling rate of the audio tracks, though video players report 48 kHz at 256 kbps for AVCHD and 48 kHz at 128 kbps for MPEG-4.

The table below shows the specs for various video recording options.

As noted above, the Sony A77 offers two video recording formats, either the HD-only AVCHD format or the less space-efficient but more computer-friendly MPEG-4. The MPEG-4 file format is a bit less efficient in its use of memory card space for a given image quality level, but is more widely supported, and seems to be a bit easier for older computers to read. AVCHD is the best choice if your primary output is going to be directly to a HD television, but MPEG-4 probably a better choice for your computer, particularly if it's more than a year or two old.

In AVCHD mode, the pixel resolution is 1,920 x 1,080, with a choice of either progressive-scan or interlaced capture. Unlike almost all cameras to date, the Sony A77's 60fps modes are true; that is to say that they're recorded from data that's clocked off the sensor at 60 frames per second, not by simply repeating every frame twice for progressive scan, and splitting every frame across two fields for interlaced video. The highest 28Mbps bitrate is not surprisingly in the 60 frames-per-second progressive scan mode, and here you have no choice of lower bitrate. For interlaced video and lower 1080p frame rates, though, you have two choices of bit rate; either 24 Mbps, or 17Mbps. If your computer is up to the task, the 60p mode offers a worthwhile improvement in fluidity over cameras that clock data off at 30 fps. It also offers the ability to halve your playback rate for a 50% slow-mo, while retaining the same fluidity you'd obtain with most other SLRs.

MPEG-4 mode offers a choice of two resolutions both recorded at 30 frames/second (progressive), with data rates and compression ratios as detailed in the table above. Note that the 1,440 x 1,080 pixel mode has rectangular pixels, meaning that it plays back with a standard 16:9 aspect ratio, but with reduced resolution on the horizontal axis. This less-common format hails from HDV camcorders. The A77 forgoes a 1,280 x 720 pixel mode altogether.

Sony recommends use of a Memory Stick PRO Duo or PRO-HG Duo Mark 2 card, or SD / SDHC / SDXC Class 4 rated memory cards for movie recording, to ensure that card write speed isn't a limiting factor in clip length. (Slower cards will likely still work to some degree, but with a reduction in clip length, especially in AVCHD mode at the highest bit rates; many competitors actually recommend a minimum of Class 6 SD cards.)

Here are some examples of video shot with our sample of the Sony A77:

Sony A77 Video-Mode Focusing

Live autofocus during video recording was traditionally one of the main areas in which SLRs and CSCs lagged dedicated camcorders, although modern contrast detection algorithms have done a lot to catch up. It's perhaps not as much of a problem as one might expect, anyway, because the lower resolution of video images results in greater effective depth of field than with high-resolution still images, but it's still proven an issue for many consumers. Arranging camera angles so the subject will stay in the plane of focus for the duration of a clip can help to some extent, as can using smaller apertures to increase the depth of field, but neither works in all situations, and provides an adequate replacement for live autofocus. Of course, you can also learn to "pull focus" while the camera is recording, moving between preset focus points manually, but doing that well requires a surprising level of skill and experience -- and it can be made even trickier with lenses that weren't designed for video use.

The Translucent Mirror design of the Sony A77 allows a near-unique selling point: full-time phase detection autofocus during video capture. (Among interchangeable-lens models, only the other Translucent Mirror cameras and Nikon's 1-series cameras can make this claim.) The availability of full-time phase detect avoids the main drawbacks of contrast-detect AF: a tendency to hunt around the point of focus, and slower AF operation, although both aren't as much of an issue as they once were. Still, there's no question that consumers and some prosumers still consider the availability of phase detect for video to be a big plus.

There are, however, some catches. Perhaps most significantly, the Sony A77's autofocus functionality during movies relies on the lens aperture being kept at or near the open position, and for this reason, manual or priority exposure control isn't available when autofocusing is enabled during movie recording. Since smaller apertures can't be used to control exposure, this further means that when autofocus is enabled, a combination of adjustments to ISO sensitivity and shutter speed must be used to control exposure in bright lighting. When higher shutter speeds are selected by the Sony A77's auto-exposure system, the result can be a noticeable choppiness, because each video frame retains less motion blur on moving subjects. (If you're intending to extract stills from your video, though, the reduced motion blur can potentially be an advantage, with moving subjects more sharply rendered.) This issue can be worked around using neutral density filters to bring the shutter speeds back down, but that of course relies on your having the appropriate selection of filters for your chosen lenses.

The Sony A77's phase detection system functions identically for both still image and movie shooting. There are a total of 19 AF points, of which 11 are cross-type points, sensitive to both horizontal and vertical detail. While these points cover a fair portion of the image frame, and it's possible to manually select which point you want to use, they cannot be moved around the frame at will, as you can do with a camera using contrast detection autofocus. (They also don't reach as near to the edges of the frame as is possible on cameras using contrast detection.) Four AF point selection modes are available -- Wide (which automatically selects any of the 19 AF points), Zone (which allows automatic selection either on the left, right, or center of the frame), Spot (which uses only the central, cross-type point), and Local (which allows direct selection of any individual point). The focusing mode and point can be changed during movie capture, useful if your subject is moving around the frame, or you want to direct the viewer's attention between multiple subjects in the scene, but this does involve some handling noise that is likely to be picked up by the on-board mics.

Regardless of the autofocus servo mode selected for still image capture, movies always use continuous servo autofocus, so it isn't possible to manually trigger single AF cycles as desired during movie capture. There is a workaround for this, in that you can simply disable and re-enable autofocus during movie recording, using the physical switch on the lens or camera body, as appropriate. Unless the camera's mounted on a tripod, though, this approach is liable to cause camera shake, and of course the sound of the switch being moved will also likely be picked up by the A77's internal microphone. Of course, it's also worth noting that noise from the autofocus drive mechanism is also likely to be picked up on the audio track, unless using an external microphone mounted remotely, or on some form of shock mount.

For more advanced users, manual focus during video recording is certainly an option, just as it is on many video-capable, interchangeable-lens cameras--and unlike video-capable DSLRs, the A77 allows framing of video not only on its LCD display, but also in its electronic viewfinder (an important advantage when shooting under bright sunlight, when LCD panel glare can make manual focusing even more challenging). The Sony A77's very high resolution electronic viewfinder makes reasonably accurate manual focus adjustment more feasible than most, even without zooming the view. With that said, though, even though it's right at the upper end of what's available in terms of resolution, it doesn't provide even half the resolution of a Full HD video frame, so you'll likely find that the AF system can still do a noticeably better job of focusing than you can manually. The Sony A77 does offer its users a potential solution for any shortcomings in their manual focusing abilities, thanks to the availability of full manual or priority exposure control when focusing manually. Presuming that there's enough light for an adequate exposure, you can simply stop down the lens further to increase the available depth of field, giving yourself a margin of error around your selected point of focus.

The availability of full-time phase detection autofocusing during movie capture remains one of the most significant benefits of the Sony A77's Translucent Mirror design, and while it doesn't provide quite the level of benefit for consumers that it did in its predecessors 18 months ago, you still can't understate the benefit of relatively fast autofocusing without obtrusive hunting. Since its Alpha-mount lenses weren't designed for video, autofocus drive noise is unfortunately quite noticeable, but that's an issue that the Sony A77 shares with most video-capable DSLRs. Probably the biggest issue in the design is the requirement that the lens aperture be held open when autofocus is active, which can result in choppy video when shooting in bright conditions. This, coupled with the inability to place a focus point outside the area covered by the phase detection AF points, are probably the most significant drawbacks of the design. Unfortunately, with the availability of full-time phase detection AF in the A77, Sony continues to choose not to provide any contrast detection AF capability. Given that both methods have different strengths and weaknesses, we'd still have preferred to see Sony offer both systems, allowing the videographer to decide which AF mode was best suited to their subject.

Real-World Video AF Performance (Or lack thereof)
As noted above, for all the promise of the Sony A77's full-time phase-detect AF system, we found it almost useless in our standard focus-tracking tests. (Note that in this context, we're using "focus tracking" to mean the ability of the camera to adjust focus in response to changes in subject distance, without changing location in the frame, vs object tracking, in which the subject moves across the frame, crossing between different focus points.)

The clips at the top of this section shows the Sony A77 trying to track a car moving at 10 mph and 20 mph, more or less directly towards the camera. After some initial failures, we thought that perhaps the lack of vertical detail in the car's grille could have been a problem (despite the A77's center AF point being cross-type), so we taped a large version of the focus target from our Indoor Portrait shot to the front of the car, to make sure the camera had something really easy to focus on. Unfortunately, this made no difference.

You can see the AF behavior most clearly in the 10 mph clip at top, where the camera makes no focus adjustment until the car is quite close, then suddenly snaps into sharp focus and tracks for a little while until the car is just too close. As soon as the car moves off the center AF point again, focus very quickly shifts to the background.

We performed this test at speeds ranging from 10 to 40 mph, across a couple of days, using first the 16-50mm kit lens, and then the 24-70mm f/2.8 Carl Zeiss optic. We thought that perhaps the better lens would improve the AF results, but they were actually somewhat worse. On some of the tests from the first day, the camera did a reasonable job of tracking, but only at 30 and 40 mph, 10 and 20 mph were as bad as seen above.

We did our first set of tests using just Spot AF, but the next day tried both Spot and Wide Area, thinking that maybe the camera might do better if we gave it more freedom in where to find its subject-distance information. As you can see above in the second 20 mph example, this made no difference.

What makes this all so puzzling is that the camera performed brilliantly when shooting in continuous still-frame mode, tracking focus very accurately across a range of speeds, until the car was very close to the camera and moving very quickly. Why did it do so well in those tests, but fail so miserably when shooting video? It's the same focus system at work in both situations, so you'd think the results would be the same.

We unfortunately have no answer to the above; we used two different lens, gave the camera a very easy, brightly-lit target to focus on, and made sure we had the latest firmware loaded beforehand (v1.06, at the time). We have to believe that this is a fixable problem, given how incredibly well the camera did in continuous still mode with the same subject under identical conditions. We've asked Sony to look into this, and will post an update here once hear back from them.

Sony A77 Video Exposure Control

While the Sony A77 lets you record movies directly from any of its still-image exposure modes, including aperture-priority, shutter-priority, and full manual exposure modes, the shutter speed, aperture, and ISO settings for video recording are always automatically controlled except when the Mode dial is in the Movie position, and autofocus is disabled. Thus, while the camera's Mode dial might suggest full PASM (programmed, aperture-priority, shutter-priority, and full manual exposure) exposure control for videos, there in fact is no direct control over aperture, shutter speed, or ISO during movie recording. (You are, however, warned that only Program exposure is available in Movie mode, if the lens isn't set to Manual focus.)

When focusing manually, the Sony A77 offers a choice of either completely automatic, Shutter-priority, Aperture-priority, or fully Manual exposure. In the latter, you get control not only of both aperture and shutter speed, but also of ISO sensitivity, allowing complete control over the exposure. Note, though, that the ISO sensitivity range is greatly reduced for video capture, with an upper limit of just ISO 1,600 equivalent. If you want the maximum creative expression, though, the ability to control all exposure variables is great, and as an added bonus you can even change all three during recording, if you're not concerned about handling noise on the camera body. Even if you're not feeling creative, the ability to stop down the aperture is a particularly useful one when focusing manually, providing a means to increase depth of field (and hence, the chance that your chosen subject is in focus.)

Exposure compensation adjustments made in still-capture modes also carry over into movie recording, provided that there's enough light. (That is, if it's too dark, boosting the EV adjustment won't make your video any brighter.) It's also possible to adjust exposure compensation during movie recording, and to lock the exposure level by holding down the autoexposure lock button. (When released, exposure metering and adjustment will immediately resume.) White balance settings also carry over to video mode, as do the metering modes, creative styles, lens corrections, Dynamic Range Optimization, and some picture effects. (Only the Soft Focus, HDR Painting, Rich Tone Mono, and Miniature effects aren't available for videos.)

Shutter speed is one aspect of video exposure we've recently become more aware of. It turns out that slower shutter speeds tend to produce more natural-looking videos than faster ones: The motion blur associated with a slower shutter speed tends to smooth-out transitions between frames with rapidly-moving subjects: Cameras with 30fps recording, but shutter speeds 1/100 second or higher produce somewhat choppy, artificial-looking movie footage, while cameras with exposure curves biased toward shutter speeds in the 1/30 - 1/60 second range show a lot more motion blur, but the end result looks more natural to the eye. The A77 is more prone to this than traditional SLRs and CSCs, because when autofocus is enabled, the aperture must remain at or near its open position to make phase detection AF possible. This results in the exposure level being controlled with only shutter speed and ISO sensitivity, where other cameras might be able to use a slower shutter speed by stopping down the lens aperture as necessary.

Sony A77 Movie-Mode Image Stabilization

Sony is unique among camera manufacturers, in having both body-based and lens-based image stabilization technology in their product lines. In the case of the A77, image stabilization happens in the body, and so it is available with all lenses. Sony claims that the SteadyShot anti-shake system in the A77 provides a 2.5 to 4.5-stop reduction in the blurring produced by camera shake. Translating that into real-world shutter speeds, a two-stop improvement means that a shutter speed of 1/30 second would give you the same resistance to blur from camera shake that a speed of 1/120 would without anti-shake. A 4-stop improvement would mean you could shoot as slow as 1/6 second and get the same results (blur-wise) as when shooting at 1/120 second unaided. Even the lower end of the specified range of effectiveness means a pretty significant improvement in one's ability to hand-hold long exposures. Since the A77 uses sensor data to provide a live view feed on the LCD display or electronic viewfinder during video capture, the effect of stabilization can be monitored.

Sony A77 Video: Audio recording

External Mic. The Sony A77's optional external stereo mic plugs into a standard 3.5mm jack under a rubber flap on the left side of the camera body.

Like most competing SLR cameras with video recording capability these days, the Sony A77 features a built-in stereo microphone, but with very little separation between the microphone ports (both housed under a single grille right in front of the flash hot shoe), a position that likely reduces the stereo effect. It also provides for recording via an external stereo microphone, courtesy of a standard 3.5mm jack located under a rubber flap on the left side of the camera body, a less common feature. Sony's only published spec for the A77's audio recording capability simply says "Dolby Digital / MPEG-4 AAC-LC", so we don't officially know the sampling rate or number of bits of A/D resolution employed, although third-party MPEG players suggest 48 kHz at 256 kbps for AVCHD and 48 kHz at 128 kbps for MPEG-4.

As with with most video-capable SLR and compact system cameras we've tested, the A77's internal microphones are exquisitely sensitive to noise produced when operating the camera's controls or even moving your hands on the body. Since the A77 accepts standard Alpha-mount lenses which haven't been designed with video recording in mind, autofocus drive noise is also clearly picked up by the camera's internal microphones, although the AF operations are at least brief and direct, perhaps resulting in somewhat less noise than in cameras using contrast detection autofocus.

As with most video-capable interchangeable lens cameras, the Sony A77 doesn't have any provision for manual audio level control, whether working from the internal or optional external mic. Of course, this isn't likely to be an issue for the A77's primary target buyers. It does, however, provide a simple on/off wind cut filter function.

Sony A77 Video: Geotagging

The A77 is rare indeed as an interchangeable-lens camera with a built-in GPS receiver. As in still image mode, the A77 can geotag its movies with their capture location -- or at least, with the location at which capture commenced. This information can be displayed on the camera's screen, and accessed by Sony's bundled software. The GPS can take several minutes to achieve its initial lock, but this process can be made faster by uploading GPS assist data from an attached computer using Sony's software package around once per month.

Sony A77 Movie Recording/Playback User Interface

The Sony A77 makes movie recording very easy, as you can initiate it at any time, regardless of the mode-dial setting: Simply press the prominent Movie Record button with the red dot at its center on the camera's top panel, and the camera will start recording video. Of course, if you want to record with manual exposure control, you can jump to the dedicated Movie position, so you get the best of both worlds--quick access while shooting stills, but total control when needed.

The A77's dedicated Movie menu is short and sweet. A full list of options can be found below:

Sony A77 Movie Menu 1:

Playback mode on the Sony A77 is--as in other recent Sony interchangeable-lens cameras--decidedly odd. The reason is that the A77's playback is an either/or (well, either/either/or) proposition, relative to stills and videos: If you've just shot a video and press the playback button, you'll see only movies that are stored on the card; not the still images. (And for that matter, only videos recorded with the same compression type you last used.) Likewise, if you've just shot a still image, you'll only see other stills when you hit the playback button. To switch between the still, MP4, and AVCHD playback modes, you have three options -- either drop into thumbnail view and scroll over to the left, then press the four-way controller to get the View Mode selection screen, or visit the Playback menu and access the View Mode menu there, or simply grab a throwaway exposure of the type you want to view. We actually found it much more convenient to hit the Movie Record button twice (to record a brief video clip) than to navigate through the playback menu to change the playback mode.

Sony introduced this playback mode in its NEX-series SLD cameras, where it caused us some consternation until we figured out what was going on. "Where'd all my movies/stills go?" RTM, as they say, but we can only imagine the dismay many users will experience (if only until they read the manual) when they think all their vacation photos disappeared after they'd finally shot a video. Since so few people actually do read manuals, we also suspect this is the source of a lot of service calls to Sony's support centers. Suffice to say, we're getting a bit tired of complaining about this design; it's unintuitive, awkward, and we find ourselves disliking it a little more with every generation of cameras that retains it. ;-)

The likely reason for this odd either/or choice for movie/still playback reveals itself when you try to scroll through movies you've recorded, to find a particular one you want to play back: Scrolling through recorded movies is just ineffably slow. Well, perhaps not ineffably; it's a matter of a couple of a second or two per movie, but that's slow enough to make navigating through more than two or three movies seriously painful. Why so slow? The camera is lightning-quick scrolling through still images, and doesn't it save a JPEG thumbnail of each movie, for just this purpose? This is another area in common with the NEX-series cameras that's going to produce a lot of frustration with users.

While it pales beside the slow playback scrolling, we missed one other playback option that's utterly commonplace on both digicams and CSCs from most manufacturers; namely the "trim" function. Whenever you record a short video clip, it's inevitable that you'll start earlier and keep recording longer than the action you're interested in. (If you don't do this, you're almost certainly going to miss action you're interested in, especially because the Sony A77 takes a second or two to actually start recording, after you press the Movie button, even if it's specifically in Movie mode.) While "padding" like this is important and necessary, we like to keep our videos concise by trimming away the extraneous material at the beginning or end of the clip after they're recorded. Many cameras support doing this in-camera these days, but the A77 does not. You could certainly import the video clips to your computer and do the trimming there, but that's awfully cumbersome. Far easier to simply trim and toss away the unwanted footage on the camera.

Rolling Shutter Artifacts

Essentially every video capable digital SLR/SLD currently on the market exhibits some level of motion-related distortion called rolling shutter artifacts. These are caused because the image data is captured and then read off the chip sequentially by rows, rather than each frame's data being captured all at once. In the case of the Sony A77, this means that image data for the last row of a given frame is captured and read out anywhere from 1/25th to 1/60th second after the data for the top row was captured. The effect on moving objects is like that of a focal plane shutter in an SLR, but more pronounced, because the video frame is read out much more slowly than the slit of a focal plane shutter moves across the sensor.

For a camera that scans video frames vertically (as all do that we're aware of), rolling shutter artifacts will be most noticeable for subjects that are moving rapidly side to side, or when the camera itself is being panned horizontally. Verticals in the scene will appear tilted to the right or left, depending on the direction of camera motion. As an example, consider the case of a camera being panned from left to right, with a flagpole or other vertical object in the middle of the scene when recording for a particular frame begins: If the top of the object was centered horizontally when the first line of the video frame is acquired, by the time the last line of the frame has been captured, the bottom of the object will have shifted to somewhere left of center: As a result, the vertical object would appear to be leaning to the right.

Computer Requirements for Viewing HD Video

A typical computer these days has little trouble dealing with still images, but high-definition video can be another matter. Depending on the file format involved, it can take a pretty beefy computer to handle HD-resolution video playback without stuttering or dropping frames. The Sony A77 supports both AVCHD and MPEG-4 recording formats, but the choice is dictated for you by resolution. The AVCHD format used at the highest resolution is slightly more space-efficient on the memory card, and displays well on HD television sets, but is one of the more compute-intensive formats, and its 1,920 x 1,080 (1080p) resolution with, potentially, a 60 frames per second capture rate means there's a lot of data to deal with. The net result is that you'll want a recent, powerful computer to play full-res, 60p high-def video files from the A77 on your computer. At lower frame rates, and for lower resolution MPEG-4 video, the requirements will be somewhat more modest. You can, of course, view your movies on an HDTV via the HDMI output.

Flash

Sony A77 Flash

The Sony A77 features a built-in, pop-up flash, which operates in either Auto, Fill-Flash, Slow-sync, Rear Sync, Wireless, and Flash-off modes. To release the flash from its compartment, press the button on the left side of the EVF housing. The release mechanism is electronic, so bumping the button when the camera is switched off won't cause the flash to pop open and get damaged in your camera bag. Close it again by pushing the flash head back down.

The main Flash modes are changed from the Function menu. In Auto flash mode (available only in the camera's Auto, Auto+, or some Scene Selection modes), the camera automatically determines when to fire the flash based on lighting conditions, and will pop-up the flash automatically. In Fill-Flash mode, the flash fires with every exposure, regardless of ambient lighting. The Rear Flash Sync mode fires the flash at the end of the shutter time, rather than the beginning. If you have moving objects in the scene with lights, such as a car, this will produce a sharp image of your subject, with a "motion trail" following behind it when shooting at slower shutter speeds. We'll come to Wireless mode in a minute. One mode isn't accessed from the Function menu, but rather, via a dedicated control: the AEL button doubles as a Slow-sync button, which sets the flash to fire for foreground fill exposure, while allowing the background to "burn in". (If the AEL button is configured to a different function, Slow-sync can be assigned to the ISO or AF/MF buttons.) The flash is off when Flash Off mode is selected, or when the flash is down in non Auto exposure mode.

A Flash control option in Record Menu 2 allows you to select between ADI flash, Pre-flash TTL, and Manual flash. The only difference between the first two is that ADI takes into account focus distance information from the lens, which can make for more accurate flash exposures -- especially with highly reflective subjects. A Red-Eye Reduction option is available through Custom Menu 1. When Red-Eye reduction is enabled, the camera will fire a few low-power flash pulses before it actually snaps the picture, to make the pupils of your subjects' eyes contract.

Flash exposure compensation can be set via the Function menu, within a range of +/- 3 stops, in 1/3-stop increments. This is in addition to standard exposure compensation.

The A77's built-in flash has a Guide Number (GN) of 12 meters or 39.4 feet at ISO 100, about typical for a consumer SLR. Maximum sync speed is a useful 1/250s. High Speed Sync (HSS) shooting with shutter speeds up to 1/4000s is available with Sony HVL-F58AM and HVL-F43AM external flash units.

The A77 also has a top-mounted hot shoe for attaching an external flash unit. The shoe design and contact arrangement are proprietary, set up for Sony's own dedicated flash units. Neatly hidden under a rubber flap on the left side of the body is a PC-sync terminal, for attaching to studio strobes.

The Wireless mode lets the Sony A77 work with compatible remote flash units with wireless capability, specifically the Sony HVL-F58AM and HVL-F43AM. Four separate control channels are available for wireless operation, to allow multiple photographers to work wirelessly in the same area without interfering with each other, and flashes can be addressed in three separate groups. Operating in Wireless mode with a compatible external flash unit, the Sony A77's flash exposure compensation adjustment can adjust the intensity of the external flash remotely, once the camera and flash unit have been initially synced to each other.

Flash Test Results

Coverage and Range
A powerful flash with somewhat narrow, uneven coverage at wide-angle.

Coverage. Flash coverage was quite uneven at wide-angle (16mm), leaving very dark corners in our flash coverage test image, though 16mm (24mm equivalent) is wider than most kits lenses. Some of the fall-off is also due to the lens itself, though the majority is from the flash. Illumination isn't terribly even vertically either, with some darker horizontal bands. Coverage was much more uniform at telephoto (50mm), though much of the image has a slightly reddish tent.

Exposure. Our Indoor Portrait test scene was bright with only +0.3 EV flash exposure compensation at ISO 100, which is less than the average compensation needed for this scene (+0.7 EV). The camera's Slow-Sync flash mode produced a very bright image at the default setting, though with a stronger orange cast from the room lighting from the longer exposure.

Flash Range
6 ft	7 ft	8 ft	9 ft	10 ft	11 ft
1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100
12 ft	13 ft	14 ft	15 ft	16 ft
1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100	1/60 sec f2.8 ISO 100

ISO 100 Range. With the 16-50mm kit lens at maximum aperture, flash exposures started out bright at 6 feet, peaked at 11 feet, and remained bright all the way to the limit of our test at 16 feet. Very good range, though the fast f/2.8 kit lens helped here.

Manufacturer-Specified Flash Range
14.0 feet ISO 100

Manufacturer Specified Flash Test. The Sony A77's built in flash is rated with a Guide Number of 12m at ISO 100, which works out to 14 feet at f/2.8. In the shot above, the A77 performs as Sony says it will, producing a bright exposure at the rated distance with its ISO set to 100. Our standard test method for flash range uses a fixed setting of ISO 100, to provide a fair basis of comparison between cameras. We've now also begun shooting two shots using the manufacturer-specified camera settings, at the range the company claims for the camera, to assess the validity of the

High ISO Noise Reduction

Sony A77 High ISO Noise Reduction

The Sony A77 offers three high ISO noise reduction settings: Low, Normal and High, with Normal being the default. The A77 user manual does not say at what ISO noise reduction kicks in, so we've included crops starting from ISO 50.

See for yourself how the three levels of noise reduction works under daylight-balanced lighting. Click on any of the crops below to see the corresponding full-sized image.

High ISO Noise Reduction Comparison Daylight-balanced illumination
	Low	Normal	High
I S O 5 0
	Low	Normal	High
I S O 1 0 0
	Low	Normal	High
I S O 2 0 0
	Low	Normal	High
I S O 4 0 0
	Low	Normal	High
I S O 8 0 0
	Low	Normal	High
I S O 1 6 0 0
	Low	Normal	High
I S O 3 2 0 0
	Low	Normal	High
I S O 6 4 0 0
	Low	Normal	High
I S O 1 2 8 0 0
	Low	Normal	High
I S O 1 6 0 0 0

It's a little difficult to tell from these crops, but it appears that the A77 applies "High ISO Noise Reduction" at all ISOs, as there are subtle differences in fine detail between the settings already at ISO 50. It starts to become more obvious at ISO 800 and above, and as you can see, plenty of noise reduction is still being applied at the lowest setting.

RAW Files

Sony A77 High ISO RAW Comparison

We often look at RAW files converted with dcraw, an excellent freeware raw converter. dcraw usually offers timely support for the latest cameras, but more importantly, it does not apply any noise-reduction, sharpening or other corrections such as geometric distortion correction to the output files. There will always be differences between RAW converters, in terms of the sort of de-mosaicing algorithms they use (the processes by which they convert the separate Red, Green, and Blue data sets to an array of full-color RGB pixels), but dcraw seems to use a fairly generic algorithm that delivers good sharpness with relatively few artifacts, and can be counted on to not apply any noise reduction if you don't want it to. (That said, looking at the ISO 6,400 and above examples below, it's clear that dcraw's de-mosaicing approach does have some tendency to produce rectilinear artifacts in response to high noise levels.)

See crops below to compare the A77's High ISO RAW image quality to a couple of leading SLRs: the Canon 60D and Nikon D7000. We also include the Sony NEX-7 here, which shares a similar if not identical sensor.

RAW Comparison with Canon 60D, Nikon D7000 and Sony NEX-7 RAW files converted with dcraw, no NR, no sharpening Daylight-balanced illumination
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 8 0 0
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 1 6 0 0
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 3 2 0 0
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 6 4 0 0
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 1 2 8 0 0
	Sony A77	Canon 60D	Nikon D7000	Sony NEX-7
I S O 1 6 0 0 0		N/A, ISO 16,000 not supported.	N/A, ISO 16,000 not supported.

Here, we can see the A77 doesn't perform as well as the 18-megapixel Canon 60D at the pixel level, though that's not a surprise given the 60D's larger photosites (4.3µm vs 3.9). The 16-megapixel Nikon D7000 also does better at the pixel level, with its larger 4.8µm photosites. (Note that the Nikon D7000 tops out at ISO 25600, not shown here.) The Sony A77's RAW files do look very similar to the NEX-7's, though they are slightly noisier. We assume the light lost through the A77's transflective mirror is to blame, requiring the A77 to amplify its sensor output more than the NEX-7 for the same exposure.

See crops below to compare the Sony A77's RAW image quality to some additional hi-resolution cameras.

RAW Comparison with Nikon D3X, Samsung NX200 and Sony A900 RAW files converted with dcraw, no NR, no sharpening Daylight-balanced illumination
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 8 0 0
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 1 6 0 0
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 3 2 0 0
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 6 4 0 0
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 1 2 8 0 0		N/A, ISO 12,800 not supported.		N/A, ISO 12,800 not supported.
	Sony A77	Nikon D3X	Samsung NX200	Sony A900
I S O 1 6 0 0 0		N/A, ISO 16,000 not supported.	N/A, ISO 16,000 not supported.	N/A, ISO 16,000 not supported.

The Nikon D3X, which is included here because it has similar resolution (24.5MP), does quite a bit better than the A77, but at four times the cost, it's not exactly a fair comparison. The Sony A900 also does better than the A77, though that's also not a surprise since it too has larger photosites, as both the D3X and A900 are full-frame models with 5.9µm photosites. The 20-megapixel APS-C Samsung NX200 does quite well, though, performing a little better than the Sony in terms of noise, with its larger 4.3µm photosites.

Pricing and availability

The Sony SLT-A77 became available in the US market from October 2011. Body-only pricing is set at approximately US$1,400, while a kit version including the Sony DT 16-50mm F2.8 SSM standard zoom lens is priced at around US$2,000. (The lens itself is also available separately, priced at around US$800.) The VG-C77AM vertical grip costs about US$300.