Sony A57 Review
|Full model name:||Sony Alpha SLT-A57|
|Kit Lens:||3.06x zoom
|Viewfinder:||EVF / LCD|
|Dimensions:||5.2 x 3.8 x 3.2 in.
(132 x 98 x 81 mm)
|Weight:||29.2 oz (828 g)
includes batteries, kit lens
|Full specs:||Sony A57 specifications|
Sony Alpha A57 Hands-on Preview
by Shawn Barnett, Mike Tomkins, and Zig Weidelich
Hands-on Preview posted: 03/13/2012
Sony's latest Alpha A57 is designed to give the standard Canon and Nikon bodies a run for their money, with a few key features that far exceed the capabilities of the two company's flagship consumer cameras. The main feature is the ability to capture images at 12 frames per second in a special crop mode, three times the speed of the competition. If you prefer full frame, you'll have to settle for only 10 frames per second. This speed is possible thanks to Sony's pellicle mirror design, which omits the moving mirror mechanism. Sony figured out, though, that their past offering just didn't have the right body size and shape to compete with the Rebel T3i and D5100 with their comparatively larger bodies, so they upgraded the body to that of the A65. As one who didn't find the A55 as appealing as I'd have liked, I find the Sony A57 body just right. In fact, I frequently confused the Sony A57 with the T3i, so I think they've made a wise choice.
The good news is, compared to the T3i, I find the Sony A57's grip better, with a nice deep recess for the fingertips, a textured, tacky grip surface, and excellent shutter button placement. Size is 5.2 x 3.8 x 3.2 inches (132.1 x 97.5 x 80.7mm), and weight without lens, but with battery and Memory Stick Pro Duo is 21.7 ounces (1.36 pounds; 618g). It has good heft and a quality feel, which is quite different from many of Sony's previous SLRs.
The excellent divot in the grip helps your hand center in the right position instantly, and the infrared remote port is set right into the surface (a good idea to prevent accidental or unauthorized activation). Just above that is the front Control dial. It's at a good angle, but I'd prefer it just a little closer to the shutter button. A depth-of-field preview button peeks out behind the lens on the lower left in this shot, and DOF preview works pretty well with the electronic viewfinder. The lens release button is just left of the lens, where it is on most SLRs. And the AF/MF switch is just beneath that, though you can't see it well from this angle. This switch enables compatibility with older, screw-drive lenses.
Bundled with the 18-55mm SAM lens, the Sony A57 seems to work well enough for the 16.1-megapixel sensor. It's also light and reasonably quiet, though not silent. I like the Mode dial on the left, with the right side left for control buttons. The mode dial has a lot of icons on it for the A57's special modes, leaving no room for a Memory Recall function. These modes are essentially the same as are found on the A65, only with new icons for the two Auto modes.
Between the proprietary hot shoe and pop-up flash you'll find the stereo microphone. It's not just a few holes, as found on most digital SLRs; Sony made it look cool. They even say it's designed to miss noise from the lens motor. Left of the pop-up flash is the electronic flash release button. There's no status LCD on the top deck, but most consumer users won't miss it at all. The Sony A57 includes wide steel strap lugs, which are preferable because they reduce rattle that can get into your videos.
There's only one difference on the back of the Sony A57, that the Zoom button has a name instead of an icon. Pressing the button activates the Clear Image Zoom function. You can either turn the front control dial to step through the zoom options, or use the rear navigation disk. Pressing the up and down arrows steps from 1x to 1.4x, then to 2.0x magnification. You can also use the left and right arrows to crop more finely. Sony tells us you'll get 100 percent of what you crop, either in the viewfinder or on the LCD.
Another important button is the Function button, which brings up a menu that lines the left and right of the screen to quickly set common functions. Above the electronic viewfinder is a proximity sensor to switch from LCD to electronic viewfinder and back. It works quickly enough most of the time, but when I've really wanted to get a shot, the delay can be jarring.
The LCD swivels downward and around to face up, down, left, right, and forward. On a tripod or table, of course, facing forward is going to be a little difficult. The LCD is big, bright, and beautiful, and seems to work pretty well outdoors.
Availability starts in April 2012, with the A57 and 18-55mm kit lens retailing for US$800, and body-only for US$700.
Sony A57 Tech Info
The Sony A57 uses the same APS-C sized Sony EXMOR APS HD CMOS image sensor seen previously in the NEX-5N.
Effective resolution is 16.1 megapixels, for a maximum image size of 4,912 x 3,264 pixels with a 3:2 aspect ratio.
Sensitivity ranges from ISO 100 to 16,000 equivalents, with everything up to ISO 3,200 available under automatic control. Using Sony's Multi-Frame Noise Reduction mode, you can achieve an effective ISO 25,600.
The SLT-A57 is still based around a Sony BIONZ processor, but it's the newer generation that was introduced with last year's models, rather than the 2010 version that featured in the Sony A55.
The change is said to allow lower noise levels (and hence better high ISO performance), as well as smoother gradations and higher overall image quality.
As you'd expect, the Alpha SLT-A57 features Sony's Alpha lens mount, and retains the unique Translucent Mirror technology that was introduced in its predecessor, the SLT-A55.
By providing for full-time phase detect autofocus, yet negating the need for a bunch of mirror-flipping to achieve it, Translucent Mirror cameras achieve phase-detect AF during video capture, and impressive burst shooting performance.
Perhaps due in part to the newer BIONZ processor, that performance has actually increased just slightly.
The A57 now offers up to eight frames per second burst shooting by default, up from six fps in the A55. If you lock the aperture open in Continuous Advance Priority AE mode, you can manage 10 fps, unchanged from the A55.
There's also a new JPEG-only Tele-zoom Continuous Advance Priority AE mode, which saves only an 8.4 megapixel image from the center of the image sensor, for the peak rate of 12 fps. Impressively, this still allows for both autofocus and exposure metering adjustments between frames.
All modes allow at least 23 full-res JPEG Fine frames. For raw shooting, burst depth is 21 frames.
The Sony A57 uses the same phase detection autofocus sensor as its predecessor, the A55.
Sony says that it has revised its object tracking algorithms, which can now recognize when your subject is facing the camera, and maintain tracking even if they turn away briefly, then turn back to face you.
The A57's AF sensor has 15 points, of which the top, middle, and bottom points in the centermost column of the array are cross-types, sensitive to both horizontal and vertical detail.
Although it has a dedicated autofocus sensor, the Sony SLT-A57 meters exposures using the main image sensor. It considers the scene as 1,200 separate zones, and offers a choice of multi-segment, center-weighted, and spot metering modes. The working range for metering is -2 to 17 EV, at ISO 100 with an f/1.4 lens. Shutter speeds on offer range from 1/4,000 to 30 seconds, plus bulb. In all respects, this is unchanged from the A55.
The A57's electronic viewfinder is still based around the same LCD panel used in the previous A55 model.
It's a time-multiplexed display, meaning that every pixel flashes red, green and blue in sequence, yielding full color at every pixel location. That gives a smoother look with less-obvious pixel structure, but causes RGB 'rainbow' artifacts with fast motion, or when you blink your eyes.
There are significant changes to the viewfinder's optics, though, and the infrared proximity sensors have now been moved above the viewfinder window, where previously they were below it.
A revised lens condenser arrangement allows you to trade off some magnification and effective resolution, to achieve a higher eyepoint. (The -4.0 to +3.0 m-1 diopter correction is unaffected by this setting.)
By default, you have 480k dot resolution and 1.04x magnification, but an eyepoint of just 23.1mm from the eyepiece lens.
Optionally, you can increase the eyepoint to 25.2mm from the lens, but the resolution falls to around 418k dots, and the magnification to 0.97x.
By way of comparison, the A55's EVF had a fixed 19mm eyepoint from the lens, and 1.1x magnification.
As well as the EVF, there's also the same TFT XtraFine LCD panel that previously featured in the Sony A55.
The A57's LCD has a 3.0-inch diagonal, a VGA (640 x 480 pixel) resolution with three dots per pixel, and a five-step brightness adjustment with automatic function.
As with the A55's LCD, that on the A57 is mounted on an articulated tilt / swivel mechanism that allows viewing from a wide range of angles.
Unfortunately, since it's a bottom-swivel design, it still won't help with framing self-portraits with the camera tripod-mounted or placed on a handy surface.
With the A57, Sony has included a piece of technology we've previously seen in the company's Cyber-shot compact cameras in an Alpha-series model for the first time. Dubbed 'Clear Image Zoom', this relies on the rather clumsily-named 'By Pixel Super Resolution' algorithms to upsample images to a higher resolution than that at which they were captured. In essence, it's a form of digital zoom, interpolating data from that on hand to fill in the blanks. According to Sony, Clear Image Zoom offers better results than competing digital zoom techniques, though, because it uses pattern matching techniques to improve the quality of the guessed data. Clear Image Zoom functions in steps of 0.1x, up to a maximum of 2x zoom beyond the actual focal length of the image, and Sony claims that the image quality even at 2x Clear Image Zoom will be "nearly equivalent" to that shot with an optical zoom at the same equivalent focal length.
One of the most unusual features of the Sony SLT-A57 is its Auto Portrait Framing function. This, again, is based on the 'By Pixel Super Resolution' tech, and when enabled, saves two copies of each image you capture. The first image is untouched; the second uses a combination of face detection to locate your subject, and then crops the image based on a rule-of-thirds algorithm for what the camera feels to be a more pleasing layout. Your dominant subject will always face towards the center of the frame, and the orientation of the recropped image won't necessarily match that of the original shot. You might shoot a landscape image, for example, which the camera decides would have been better as a portrait. So... where does 'By Pixel Super Zoom' fit into the picture? The answer is that the Sony A57 will--after finishing cropping your image to create a masterpiece--resample the result back up to the same resolution as the original shot, thereby making it seem as if the camera has simply gone back in time and retaken the image with different framing. You can of course disable the function, but for those who find it tricky to remember and apply the rule of thirds, it could prove an interesting feature.
Of course, the A57 also includes a variety of other creative options, most of which were present in its predecessor. One that wasn't is the Picture Effects function, which has 11 modes, and a total of 15 possible effects. These include options like Retro Photo, Toy Camera, and HDR Painting, catering to those who prefer to do their post-processing in-camera. Other creative functions include a Multi-Frame Noise Reduction mode that effectively raises the upper limit on sensitivity to ISO 25,600 equivalent, a High Dynamic Range mode that combines multiple shots in-camera to yield a single image with broader dynamic range, and a Dynamic Range Optimizer function that tweaks the tone curve automatically or manually to bring out shadow detail without sacrificing highlights. There's also a choice of both 2D and 3D panorama modes that automatically capture and stitch images as you sweep the camera past your chosen scene, then save the result as a single panoramic image.
Video is a big strength of Sony's Translucent Mirror cameras, thanks to their ability to use full-time phase detection autofocus during video capture. (Note, though, that most Alpha-mount lenses predate the SLT cameras, and hence may cause objectionable noise in the audio track while the autofocus drive is operating.)
Like many of Sony's recent cameras, the A57 provides full manual exposure control for video capture.
The SLT-A57's video capture still tops out at Full HD (1,920 x 1,080 pixels), but it now uses AVCHD 2.0, rather than standard AVCHD. That means Sony can now offer a choice of 60p, 60i, or 24p capture at this resolution, instead of the fixed 60i of the Sony A55. (If you're not in the US, you may substitute 50p, 50i and 25p for the above.)
There's still a choice of two reduced-res 30 fps modes, in MP4 format: either 1,440 x 1,080 or VGA (640 x 480).
Like its predecessor, the A57 caters for movie audio with both a built-in stereo microphone in front of the proprietary flash hot shoe (shown above), and a standard 3.5mm jack for stereo, plug-in power microphones.
The A57's built-in popup flash is almost unchanged, although it does now recharge in three seconds, rather than four. It still has a GN of 10m at ISO 100, and 18mm coverage. X-sync is 1/160 sec., and the A57 supports wireless flash.
In the contours of the handgrip, a small window conceals both an infrared remote receiver (compatible with the optional RM-DSLR1 remote), and a self-timer lamp.
As well as the mic jack we've already discussed, there's a variety of other connectivity options behind rubber flaps on the left of the camera body, including a DC input, wired remote terminal, and high-def HDMI video output.
Note that although Sony offered a version of the A55 with a built-in GPS receiver in some markets, that apparently won't be the case with the A57.
The A57 includes a single card slot on which to store images and movies. It's compatible with either the relatively commonplace Secure Digital cards (including SDHC and SDXC types), or with Sony's proprietary Memory Stick PRO Duo and PRO-HG Duo cards.
Power comes courtesy of an NP-FM500H InfoLithium M rechargeable battery pack, rather than the NP-FW50 pack used in the earlier camera.
The new cell packs 53% more power, and when using the LCD monitor, battery life has increased by about 55% to 590 shots.
The EVF still yields less battery life, but not by as great a margin as was the case with the A55. Now, you'll get around 550 shots through the viewfinder.
Sony A57 Shooter's Report
by Shawn Barnett
As I've mentioned, I'm pretty happy with the bigger, more solid build of the Sony A57. It's more like what I'm used to using, and doesn't look sickly, as the A55 did to my eye. It's also not obnoxiously thick like the A500 series seemed. The Sony A57 is trim but solid, just what North American SLR buyers have been gravitating toward for years. No more stylish two-tone body shells, no more colors. Just a handsome, well-designed camera that can tear off more frames in a second than most professional SLRs.
What's more, it does it quietly. As I shot with the Sony A57 at my son's baseball game over the weekend, I was surprised when I pressed the shutter for the first time. It wasn't making a racket, just a gentle, swift winding sound that sounded pretty futuristic. The same is true when you're out shooting street shots. The shutter sounds more like a lens focusing than a shutter firing, which is pretty stealthy when you think about it, because no one's sure you took a picture. Meanwhile, that sharp, vibrant LCD is serving up your image.
I tended to forget that the Sony A57 wasn't truly an SLR, so it was a little odd at first when I again faced the delay when I put my eye to the viewfinder. I had to check to see if I'd left the lens cap on. But otherwise, it's pretty natural to shoot with the Sony A57 in Auto Viewfinder mode, because it smartly switches between the two depending on how you want to shoot in that moment. In bright light, I still run into the shock when I go from outdoor light to the comparatively dimmer LCD in the EVF, but that's pretty normal for EVFs in general.
I have to say, I've really warmed to the Sony SLT cameras. They're fast, AF is always the same regardless of whether I use the LCD or EVF. With some competing SLR designs, I always have to remember that contrast-detect AF in Live View is going to be much slower.
While out shooting, I kept to the fast frame rate and HDR modes. Waiting for our new baseball players to hit the ball, I racked up quite a pile of images. About 600 total. The one I show here is not the best, but the boy's face is not visible, which is better for all involved. This sequence also has three images that include the ball. Because the 12-frame-per-second mode is a crop-frame mode (cropped to 8.4-megapixels), I had to step back further than I wanted, allowing more of the chain link fence to come into focus. I had only brought Sony's excellent 70-200mm f/2.8 lens, so I didn't have much choice. (see the Gallery for the full-res images)
For most of the other shots I played with DRO and HDR, shooting into doorways to see how well they would work. Some of the shots I took with HDR and DRO off were brighter than the ones I took with them on, perhaps due to minor framing differences or a different metering strategy depending on the mode. HDR in particular was interesting because it wouldn't just save one shot, but two: The first shot captured, then the combined HDR image. I know it was the first shot because a few of my images that were not included in the gallery have cars moving through them, but that doesn't tell me whether it was the high, low, or middle exposure.
|DRO/HDR Off||DRO Auto|
|HDR Auto (non-HDR "normal" image)||HDR Auto On|
Here are a few other random Gallery images. We'll have more tomorrow, hopefully with better weather, including more images from the lab.
|1/60, f/4, ISO 160||1/60, f/4, ISO 200||1/60, f/4, ISO 125|
|HDR Auto||1/100, f/5.6, ISO 160||1/80, f/5.6, ISO 100|
Overall, we're pretty impressed with the Sony A57. It seems like an ideal camera for any kind of photography. I don't generally get jazzed about unusual modes like HDR, and I seldom go for resolution-enhancement technology, as is found in the Clear Image Zoom function, but I'll still give it a try. What's most impressive is having access to 12 or even 10 frames per second in a sub-$800 camera. Add full-time autofocus while you shoot movies or stills, and the Sony A57 has what it takes to run the other guys over. And while it seemed gimmicky a few years ago, I really enjoy sweeping out a panoramic image without much thought or effort, something the Sony A57 makes easy. We'll reserve final judgment for a production unit, but so far, this is Sony's most competent consumer camera offering ever, one that should give the big two camera makers chills.
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