Sony A7S Field Test Part I

First impressions, handling and oh my, high ISO!

By William Brawley | Posted: 08/26/2014

Handheld fireworks. While this isn't a typical long-exposure-style fireworks shot, I was more impressed with the detail captured in the buildings, even at ISO 20,000!
Sony A7S + FE 70-200mm f/4: 116mm, f/4, 1/125, ISO 20,000

Initial impressions

The moment I heard about the Sony A7S and its significantly larger pixels and low-light capabilities, I was very intrigued. Eschewing the ever-increasing megapixel race of many modern digital cameras, the Sony A7S packs a "measly" 12-megapixel resolution. However, these 12 megapixels are spread over a large 35mm full-frame sensor area thanks to larger individual pixels. What this means is that while you probably won't want to print billboard-sized images from an A7S, you can shoot in vastly lower lighting with much higher ISOs, as the sensor has much more light-gathering capabilities thanks to its larger photo-sites.

With a background in photojournalism, I often found myself on assignments shooting in situations where using a flash was disruptive or downright forbidden, such as in courtrooms or on the sidelines of football or basketball games. As such, having to shoot at higher ISOs was very common, and I often wished I could bump up the ISO a little more to get a more usable exposure, but I was limited to my cameras' high ISO capabilities. Now, with the A7S, my first thought was could this camera be the perfect photojournalist camera?

For pretty much all shooting situations but sports -- where traditional phase detect AF systems still come out on top against mirrorless cameras for continuous AF performance -- the Sony A7S could be an ideal solution, for journalists, for street shooters, for travel photographers, and even landscape and astrophotographers: compact and lightweight for much better portability than a DSLR while still keeping a full-frame sensor and with practically a "shoot-in-any-lighting" ISO sensitivity range.

The Sony A7S + Sony Zeiss FE 24-70 F4 compared to a Canon 5D Mark III + 24-105 F4 IS. While both share a full-frame sensor, both the body and relatively comparable zoom lenses are notably smaller and more compact.

Aside from the large pixels and lower overall image resolution, an interesting and very beneficial side effect to having only a 12MP resolution is the smaller resulting files sizes. Super-high resolution images from cameras like the Sony A7R and Nikon D810, especially RAW files, can become very large, often necessitating the need for bigger storage, both in memory cards and in hard drives. While those two things are getting cheaper by the minute these days, larger files also require more computational horsepower and time, as you wait for images to transfer. As someone who uses a rather lightweight Apple MacBook Air for my primary computer, editing smaller files speeds up the workflow a lot. For example, an ARW RAW file from the A7S is about 12-13MB, whereas the A7R can produce RAW files that tip the scales at nearly 40MB! For someone like a documentary travel photographer, a photojournalist out in the field, or someone who simply doesn't need to make very large prints, the smaller image files from the Sony A7S can help immensely with file storage space as well as photo import and transmit times. (Of course, you can also choose smaller files sizes on the other mentioned cameras.)

Design and handling

I love the design of the Sony A7/A7R/A7S cameras… for the most part. The smooth, almost-chiseled lines and angles look modern yet somewhat retro in appearance. It's a very cool-looking camera. But looks will only get you so far. If a camera looks great, but is barely functional, then we have a problem.

Thankfully, the ergonomics of the camera aren't hampered by design very much. While the leatherette/rubber-coated handgrip is a bit shallow compared to a full-size DSLR, it feels great, and the contour fits nicely in my medium-to-large sized hand. Using the medium-sized Sony FE 24-70mm f/4 Zeiss lens, the combination feels very well balanced with the grip allowing for a very comfortable, secure hold. Even with larger, heavier lenses, such as the FE 70-200mm f/4 -- which can often be unbalanced and a little unwieldy on smaller, lighter mirrorless cameras -- they feel comfortable and balanced on the A7S (even without the accessory battery grip, which we unfortunately didn't receive for our review).

As for buttons and controls, the Sony A7S is fairly straightforward with dedicated PASM and exposure compensation dials that each have a nice, solid feel. And while neither are locking dials, they have a firm resistance and click to them, so accidental adjustments should be rare.

My main gripe regarding ergonomics on the A7S is regarding the front finger control dial. I like the rear dial just fine, as it sits right above my thumb and rotates how I expect it to do. The front, on the other hand, is strange -- it's on the wrong plane. With my finger over the shutter button, having the front dial sit lower down and rotate horizontally rather than vertically felt awkward to me.

How the A7-series front dial is (left), and how I wish the A7-series front dial was (right). Note: If it's not painfully obviously, the right image is a quick Photoshop mock-up.

I often found myself having the take the camera down from my eye to find the front control dial. I kept inadvertently trying to rotate the front dial vertically, after years of muscle memory thanks to Canon DSLRs, which have a front dial that not only rotates vertically, but also sits behind the shutter button on the same surface. When I hold the A7S, the natural position for my finger puts it over the shutter release, but in that position, the front control dial is a little too low down for my taste. I realize this a quite subjective "gripe," and your mileage may vary, but it's something I noticed right off the bat when I picked up the camera.

Apart from my issue with the dial, handling the Sony A7S is great. The built quality is excellent, with its solid magnesium body, just like A7R. While not specifically listed on the Sony A7S product page itself, Sony indicates that both the A7 and A7R cameras have dust and moisture resistance. Since the A7S shares the same full magnesium alloy build, one could assume the same level of build quality. However, when I asked about this, Sony confirmed "that there is no difference in the dust / moisture resistance capabilities of any of our A7 series cameras."

Nevertheless, the A7S feels like a very tough, well-built camera, though this is probably a "ding" against it being the "perfect photojournalist camera," as some shooting scenarios that many photojournalists experience such as strong adverse weather, heavy downpours, or rough and dusty locations such as deserts or even war zones could be an issue for the A7S. While we don't plan on visiting any deserts or drenched tropical rain forests any time soon, we hope to investigate the weather sealing in the future.

Of course, high ISO isn't the only trick up the A7S's proverbial sleeve. Low ISO shots with the big full frame sensor look very nice with excellent colors, nice shallow depths of field when you want it, and still enough detail even with only 12MP.
Sony A7S + FE 27-70mm f/4 Zeiss : 70mm, f/4, 1/800, ISO 100

Shooting with the A7S

So far, I've been extremely pleased with the shooting experience with the Sony A7S, apart from my minor ergonomics quibbles. While the A7S doesn't have the on-chip phase-detect AF system as the A7 and, rather, uses the contrast-detect-only system like the A7R, I found focusing performance on the A7S to be quite decent, even in low-light situations. This is a big plus considering its low-light/high ISO performance is one of its hallmark features.

Having a contrast-detect AF system, focusing on low-contrast and very small subjects can be tricky, and I found this to be the case at times on the A7S. In very dark locations -- such as in near full darkness where Auto ISO shot all the way to 409,600 at f/4, for example -- and I turned off the AF assist lamp, I experienced a noticeable slow-down in focus acquisition speed. If you don't mind the very bright orange focus assist lamp, then focusing in very dark locations is actually not a problem; it's slightly slower but certainly usable. To deal with very small subjects, Sony has thankfully included variable-sized focus points -- small, medium and large Flexible Spot focus modes -- that let you adjust the size of the focusing target to help pin-point your focus.

I've ended up using Flexible Spot AF mode for the majority of the time, as it allows for quick and easy adjustment, not only of the AF point size, but also the location of the AF points around the frame. The A7S makes it very quick to adjust the focus point by assigning Focus Setting to the custom C1 button next to the shutter button.

Sony A7S + FE 70-200mm f/4: 200mm, f/4, 1/60, ISO 51,200

As a long-time DSLR user, I like a good viewfinder, and the EVF on the A7S is very good. The EVF feels large and bright with crisp text and none of the RGB tearing artifacts that I've encountered with lower quality EVF screens. I also didn't find lag to be much of an issue, even as a long-time OVF fan. Despite being a mirrorless camera with the ability to compose using the rear LCD, I'm much more of a traditionalist in this regard -- give me a nice EVF, and my shooting experience is much nicer, more comfortable and more stable.

It's also great that the EVF on the A7S is good because the rear LCD can actually be quite difficult to see in bright sunlight. It's prone to glare and finger prints, and the default brightness level seems quite low in bright, sunny conditions. If you need to use the rear screen or prefer to, the brightness can be adjusted brighter by two increments (and -2 increments, if in a dark location). There's also a shortcut in the brightness menu setting for "Sunny Weather" that quickly boosts the screen brightness up to maximum. However, be careful, as keeping the brightness will burn through your battery quicker.

Another minor quibble is the lack of a touchscreen. One of my favorite features on my Olympus E-M1 is the ability to use the touchscreen to quickly adjust the focus point. It really makes it simple and fast when composing a shot, and you quickly tap on the screen to get the focus right where you want it without resorting to the focus-and-recompose method. While this clearly isn't a deal breaker for the A7S for me personally, it's a small detail that I wish Sony had included on the camera.

Last but not least, is one of the coolest features of the A7S, which was added recently in a firmware update: silent shooting mode. This update makes the camera completely silent with no shutter sounds whatsoever (though, interestingly, it will still beep when confirming focus in AF-S mode, so be sure to turn that off, too, which is oddly listed as "Audio signals" in the menus). Street photographers looking for a stealthy camera need look no further. Photojournalists can also particularly benefit from this feature, especially when photographing in sound-sensitive locations or events such as press conferences, courtrooms or live performances where loud shutter sounds can be distracting and disruptive.

Sony A7S + FE 24-70mm f/4 Zeiss : 24mm, f/4, 1/60, ISO 40,000

Low-light image quality

In my first assessment as to the image quality performance of the Sony A7S, why not start with it's hallmark feature? High ISO. With the ability to crank the sensitivity up to a whopping 409,600, the A7S is capable of shooting in practically any location, be it outdoors, indoors, at night, in bright lighting or in practically no lighting.

Eager to see the high ISO performance, I put the Auto ISO range from 100 to the maximum of 409,600 and set off to shoot, well, anything really; I could pretty much take a photo of anything regardless of light level and get a decent exposure for the most part. In that regards, the camera is pretty nuts.

However, a little reality-check, first. Are shots in the ISO 100,000+ range even usable? Well, that depends on your definition of 'usable.' If you're a photojournalist, for instance, getting the shot is what matters most, and if in your situation, an ISO level of 256,000, 320,000 or even 409,600 for whatever reason is called for to get the shot, then this camera can deliver -- getting the shots are better than none at all. However, yes, shots taken at this ISO are extremely noisy, with lots of luminance and chroma noise even after in-camera JPEG noise reduction is applied. However, the level of detail in these extreme ISO shots was simply impressive!

Comparison of Noise Reduction processing at ISO 409,600. Click for full-resolution images:
Normal: JPEG, RAW | NR Off: JPEG, RAW | NR Low: JPEG, RAW

Sony A7S + FE 24-70mm f/4 Zeiss : 70mm, f/16, 1/640, ISO 409,600

The Sony A7S is one of the best available light cameras out there. From shooting in a darkened living room to nighttime crowd shots during Fourth of July fireworks, the A7S was a blast to use and could capture images unlike any camera I've used before. Sure the photos were extremely noisy, I would never intend to print an ISO 160,000 photo at 16 x 20 inches, but for being able to "get the shot," the Sony A7S is fantastic. And this translates to really good performance once you get to the more common ISO ranges as well.

Yes, ISO 409,600 is extremely noisy, however the detail that remains in the image is very impressive. This was taken in nearly-complete back in a window-less bathroom with only a bit of ambient light though the door. Click image for the full-resolution JPEG (shot in Extra Fine-quality JPEG).
Sony A7S + FE 24-70mm f/4 Zeiss : 70mm, f/4, 1/80, ISO 409,600
Another extremely dark scene, this time on a unlit bookcase in a darkened living room.
Sony A7S + FE 24-70mm f/4 Zeiss : 54mm, f/4, 1/60, ISO 160,000

Up next

I shot some additional photos in proper lighting and during the day, and unsurprisingly, the photos looked excellent with lots of fine detail and great color -- for those, please check out the Sony A7S Gallery! In my next installment, I'll dive further into the image quality of the A7S with its sensor's supposed excellent dynamic range capabilities. I'll also investigate its extensive video recording prowess, with both its higher quality XAVCS Full HD video as well as uncompressed 4K output features. Stay tuned!

Sony A7S + FE 24-70mm f/4 Zeiss : 70mm, f/4, 1/320, ISO 100


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