Sony A7S Review
|Full model name:||Sony Alpha ILCE-A7S|
(35.6mm x 23.8mm)
|Viewfinder:||EVF / LCD|
|Native ISO:||100 - 102,400|
|Extended ISO:||50 - 409,600|
|Shutter:||1/8000 - 30 seconds|
5.0 x 3.7 x 1.9 in.
(127 x 94 x 48 mm)
|Full specs:||Sony A7S specifications|
With a unique 12-megapixel 35mm sensor, the Sony A7S able to shoot in very low light with impressive high ISO performance up to ISO 409,600! The sensor is tailor-made for 4K video for excellent detail, plus very wide dynamic range. XAVC S high bitrate format provides higher quality Full HD video, plus expanded pro-level video features such as SLog2 gamma make for a solid hybrid photo/video camera.Pros
Outstanding high ISO performance; excellent dynamic range; 4K video recording (via uncompressed HDMI); XAVC S option for HD video; Slightly improved battery life over A7/A7R; Built-in Wi-Fi & NFC connectivity.Cons
4K video requires expensive external recorder; Sluggish startup time; Loud shutter; Silent Shooting mode hurts image quality; Lacks a built-in, pop-up flash; Limited selection of native Sony FE lenses.Price and availability
The Sony A7S began shipping July 2014, and is available soley in a body-only configuration for around $2,500.Imaging Resource rating
4.5 out of 5.0
$6314.54 (61% more)
18 MP (32% more)
Also has viewfinder
24 MP (49% more)
Also has viewfinder
$7145.10 (65% more)
24 MP (49% more)
Also has viewfinder
$1850.00 (34% less)
16.3 MP (25% more)
Also has viewfinder
Sony A7S Review
04/09/2014: Added Sony A7S vs. A7R/A7 comparison table
05/16/2014: Added pricing and availability info
08/26/2014: Field Test Part I - First impressions, handling and oh my, high ISO!
10/27/2014: Field Test Part II - Dynamic Range Performance & Video Recording
11/07/2014: Image Quality Comparison and Print Quality Analysis
12/12/2014: Review-wrap and final Conclusion posted
Sony really redefined what full-frame photography could be in the fall of 2013, with the introduction of the A7 and A7R, by far the smallest full-frame, fully-featured interchangeable lens cameras we'd seen to date. Now, the Sony A7S is poised to similarly redefine the world of 4K video and low-light still shooting.
Rather than chasing ever more pixels, the Sony A7S takes a conscious step back, featuring an all-new 12.2-megapixel sensor with huge pixels -- by current standards, at least -- as well as some unique tweaks aimed at increasing dynamic range. The combination equates to unprecedented low-light performance. By default, the Sony A7S has a sensitivity range of ISO 100 to 102,400 equivalents for still imaging or video. This range can be expanded for still shooting to encompass everything from ISO 50 to 409,600 equivalents in still shooting, and ISO 100 to 409,600 equivalents for video.
While we saw a similar ISO range from the Nikon D4s, the Sony A7S's bigger pixels and special sensor architecture offers lower noise levels and better detail -- albeit at a lower resolution.
There's some new sensor technology at play in the Sony A7S, beyond just its bigger pixels. We were told that the A7S sensor can, with some paraphrasing, "adjust its gain corresponding to its environment. It essentially adjusts its dynamic range accordingly, so that it is able to optimize the dynamic range for each ambient environment, whether dark, bright, harsh lighting, etc."
That's intriguing, but doesn't really tell us much about how it actually works. However Sony did say that it expects a dynamic range of up to 15.3 stops from the A7S in raw format.
Another important feature for the A7S is the ability to use a Silent Shooting mode. This allows fully-silent shooting with both electronic first and second-curtain functions, not simply a reduced noise level with electronic first-curtain and mechanical second-curtain, as in some competing cameras.This is a huge feature for nature shooting, or any other environment in which silence is key.
No less important is the fact that the chip can output extremely high-quality, 16:9-aspect, 4K video without line-skipping, pixel binning or downsampling. It's not quite a native sensor readout, as there's still an approximate 1.1x focal length crop, but it's the closest to full-sensor width video we've yet seen from a full-frame imager. By contrast, Canon's EOS-1D C has a 1.3x focal length crop for 4K video, using only an APS-H sized area of the sensor.
The Sony A7S can't record 4K video directly, but can output an uncompressed 4:2:2 4K video feed via HDMI. You can use the same approach for Full HD video, or alternatively, opt for a choice of XAVC S or AVCHD codecs. Vanilla MP4 is also possible at 1,440 x 1,080 or below.
The A7S' near-full width 4K mode means you maintain most of the wide-angle capability of your lenses, have more of the shallower depth of field of full-frame area, and still avoid the sort of artifacts caused by the line-skipping approach used in almost all other DSLRs.
It's also important to note that the Sony A7S can't record 4K video directly to the internal memory card, but rather passes a clean, uncompressed (8-bit, 4:2:2) 4K 30p/24p stream over its HDMI connection, where it can be recorded on an external device. The reason for this is that the processing required to encode and record the 4K signal internally would have generated far too much heat within the camera body.
The A7S can record full HD video internally, though, and even offers a choice of AVC codecs. Beyond the standard AVCHD format, the Sony A7S also supports the XAVC S codec, previously found only in Sony's high-end Handycam professional camcorders. The XAVC S codec was designed to be able to accommodate 4K video, but in the case of the A7S provides high-bitrate full HD, at 50 Megabits/second.
At Full HD resolution (1,920 x 1,080), the Sony A7S can record at frame rates of 60p, 60i, 30p, and 24p directly to the card. The camera can also record in APS-C mode -- what Sony calls "Super 35mm-equivalent" -- if desired, and in that crop mode can support a high 120 frames per second rate while shooting at 720p (1,280 x 720 pixel) resolution, creating a 5x slow-motion effect.
The Sony A7S also supports what's known as S-Log2 gamma, a tone curve borrowed from Sony's pro video recorder line that greatly expands the practical dynamic range of its videos. This special gamma function applies a strong logarithmic tone curve to the sensor's output, rolling off the highlight end of the curve to preserve highlight detail. Viewed without a corresponding tonal expansion, the resulting video will look very flat, but the dynamic range is expanded over linear encoding by 1,300%, providing enormous dynamic range that can be exploited in post-production.
Other pro-level video functions include the ability to save "picture profiles", that include settings like gamma, black level and color adjustments. These settings can be shared across multiple A7S bodies, to ensure consistency in multi-camera shoots. The Sony A7S also provides time-code (free-run and rec-run), the ability to synchronize with external devices, marker and zebra displays on both the LCD screen and viewfinder, and can record dual XAVC S as well as MP4 simultaneously (MP4 at 1,280 x 720/30p).
As with other cameras in Sony's line, the A7S has what the company terms the Multi-Interface Shoe, a proprietary hot-shoe that can provide XLR audio input via the XLR-K1M adapter kit. As part of the A7S announcement, Sony also said that it was developing another mic adapter kit "allowing use of professional microphone systems", but gave no further details. (Perhaps a system that would provide 48-volt phantom power over the XLR connection? We don't think the current K1M adapter provides that.)
Like the A7R, the Sony A7S lacks on-chip phase-detection autofocus elemen`ts, so it uses the same "Fast Intelligent AF" as the A7R, a system based solely on contrast detection. Sony promises better autofocus performance on the A7S, though, thanks to the larger pixels on its new sensor. In fact, for low-light autofocus it's one of the best on the market, able to focus right down to light levels of -4EV, with an f/2.0 lens. (This is one of the lowest-light AF capability we've ever heard of, by a full EV step.)
|Differences between the Sony A7S, A7R and A7|
|Camera||Sony A7R||Sony A7S||Sony A7|
|Body-only List Price||US$2,300||US$2,500||US$1,700|
|Available in Kit with Lens||No||No||Yes|
|Body Materials||Magnesium alloy||Magnesium alloy||Magnesium alloy and polycarbonate|
|Sensor Size||35.9 x 24.0mm||35.8 x 23.9mm||35.8 x 23.9mm|
|Sensor Resolution (Total)||36.8 mpix||12.4 mpix||24.7 mpix|
|Sensor Resolution (Effective)||36.4 mpix||12.2 mpix||24.3 mpix|
|Maximum Image Size||7,360 x 4,912 pixels||4,240 x 2,832 pixels||6,000 x 4,000 pixels|
|Standard ISO sensitivity (Still)||100 - 25,600||100 - 102,400||100 - 25,600|
|Expanded ISO sensitivity (Still)||50 - 25,600||50 - 409,600||50 - 25,600|
|Standard ISO sensitivity (Video)||200 - 25,600||200 - 102,400||200 - 25,600|
|Expanded ISO sensitivity (Video)||N/A||200 - 409,600||N/A|
|Electronic First Curtain Shutter||No||Yes, optional||Yes, optional|
|On-chip Phase Detect Pixels?||No||No||Yes|
|Continuous Shooting Rate
(with continuous autofocus)
|1.5 fps max.||2.5 fps max.||2.5 fps max.|
|Speed Priority Continuous Shooting Rate||4.0 fps max.
(No Continuous AF)
|5.0 fps max.
(No continuous AF)
|5.0 fps max.
(Continuous AF supported)
|Autofocus Type||Contrast Detection
|Fast Hybrid AF
117-point (phase detect)
25-point (contrast detect)
|Predictive Autofocus Tracking||No||No||Yes|
|Flash Sync Speed||1/160 second||1/250 second||1/250 second|
|Maximum resolution for HDMI live view||1,920 x 1,080 pixels||3,840 x 2,160 pixels||1,920 x 1,080 pixels|
|Video codecs||AVCHD / MP4||XAVC S / AVCHD / MP4||AVCHD / MP4|
|Maximum clip length||29 min. (AVCHD); 20 min. / 2GB (MP4)||29 min. (XAVC S); 29 min. (AVCHD); 20 min. / 2GB (MP4)||29 min. (AVCHD); 20 min. / 2GB (MP4)|
|120fps at 720p?||No||Yes||No|
|S-Log 2 gamma option||No||Yes||No|
|Picture profile function||No||Yes||No|
|Maximum Magnification (Playback)||23.0x||13.3x||18.8x|
|Battery life (Still)||340 shots (LCD)
270 shots (EVF)
|380 shots (LCD)
320 shots (EVF)
|340 shots (LCD)
270 shots (EVF)
|Battery life (Video, clips with power-cycling and zoom)||60 min. (LCD); 65 min. (EVF)||60 min. (LCD); 55 min. (EVF)||65 min. (LCD); 60 min. (EVF)|
|Battery life (Video without power-cycling or zoom)||90 min. (EVF / LCD)||90 min. (EVF / LCD)||100 min. (EVF / LCD)|
|Weight (Body Only)||14.4 ounces (407g)||15.7 ounces (446g)||14.7 ounces (416g)|
|Weight (with battery and
Stick PRO Duo flash card)
|16.4 ounces (465g)||17.2 ounces (489g)||16.7 ounces (474g)|
In continuous shooting mode, the Sony A7S offers the same performance as the A7 before it: 5 frames per second in speed priority mode, which locks focus from the first shot in the series, or 2.5 fps with autofocus adjustment between frames.
CIPA-standard battery life for still shooting is rated at 380 shots per charge when using the rear-panel LCD, or 320 shots with the electronic viewfinder.
From all the above, it's clear that Sony had video recording -- and particularly 4K video recording -- firmly in mind when it developed the A7S. It'd be a mistake, though, to focus solely on that and assume that it's not a camera meant for still photographers as well.
The sensor's big pixels and special dynamic-range management capabilities mean it should provide unprecedented low-light capability for still shooters, too, and have very well-controlled noise levels when using high ISOs to freeze action under more moderate lighting as well.
Sony started shipping the A7S in the US market from July 2014. And good news: Body-only list pricing is set at an impressively aggressive US$2,500!
Place your order with a trusted Imaging Resource affiliate now:
The Sony A7S is clearly aimed at videographers -- but it offers a whole lot that should prove very exciting to stills photographers, too!
Sony A7 Field Tests
Sony A7S Field Test Part I
First impressions, handling and oh my, high ISO!
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.
Read more about my hands-on experience and the high ISO performance of the Sony A7S.
Sony A7S Field Test Part II
Dynamic Range Performance & Video Recording
Apart from the absolutely stunning high ISO performance of the new Sony A7S camera, another hallmark feature Sony is touting its dynamic range performance. At a stated 15.3-stops of dynamic range, the A7S should give photographers plenty of flexibility to reign in those highlights without clipping and lift up and reveal shadow details without a lot of noise. The primary reason why I personally shoot in RAW is the extra latitude it gives me to adjust images as I see fit, especially shadow and highlight details, as well as white balance, sharpness and noise reduction. In this installment of my A7S Field Test, I'll put the dynamic range capabilities of the camera to the test. I took the A7S along with me to Photokina in Germany, and I made sure to capture some challenging photos with strong highlights and deep shadows.
And last but not least, I'll go into detail with the other major feature of the A7S: video recording. With the specially-designed "4K-optimized" sensor with full-pixel readout, as well as a new higher quality XAVC-S video format, like the Panasonic GH4 I reviewed earlier this year, the Sony A7S is clearly designed to do double duty for both stills and video shooters. Let's see how it stacks up.
See the A7S's impressive dynamic range and video chops!
Sony A7S Image Quality Comparison
The 12-megapixel A7S goes head-to-head with the competition
Below are crops from our laboratory Still Life target comparing the Sony A7S with the Sony A7, Canon 5D Mark III, Fujifilm X-T1, Nikon D750 and Panasonic GH4. All of these models sit at relatively similar price points and/or categories in their respective product lineups as advanced enthusiast or professional-level cameras.
These comparisons were somewhat tricky to write, as the cameras vary a great deal in resolution, so bear that in mind as you're reading and drawing your own conclusions. (We generally try to match cameras in these comparisons based on price, given that most of us work to a budget, rather than setting out to buy a given number of megapixels.)
NOTE: These images are best quality JPEGs straight out of the camera, at default settings including noise reduction and using the camera's actual base ISO (not extended ISO settings). All cameras in this comparison were shot with our very sharp reference lenses. Clicking any crop will take you to a carrier page where you can click once again to access the full resolution image as delivered straight from the camera.
Sony A7S Print Quality
Not just digital. The A7S looks pretty great in the real world, too.
Despite having a rather meager 12-megapixel resolution, the full-frame Sony A7S manages some impressively large print sizes at his lower ISOs. Pushing the resolution of the sensor, you see some pixelation at very close inspection, but from a normal viewing distance, the prints are crisp, detailed and display nice, pleasing colors. At the typically higher ISOs of 3200 and 6400, noise is well controlled at these ISOs, mainly confined to the shadow areas, and colors still look great.
Sony A7S Conclusion
A low-light powerhouse with professional, 4K video capabilities
With the A7S, Sony steered away from the megapixel race and offered a rather unique option for their customers: a large, full-frame sensor with only 12 megapixels. To create such a sensor, the individual pixels are made significantly larger than the pixels on, say, Sony's 24.3MP A7 and 36.6MP A7R cameras. Thanks to these larger pixels, the sensor is able to gather much more light per pixel, giving the Sony A7S outstanding high ISO and low-light performance.
In our tests and real-world shooting, the A7S lives up to its claim as a low-light shooting behemoth! For both still images and video, the Sony A7S can take photos in practically any lighting condition, even in near-complete darkness. Of course, with a maximum sensitivity going up to ISO 409,600, the A7S definitely produces noisy images at these extremely high ISOs, but nevertheless they are still able to show fine detail. Impressive. And it's not just the low-light image quality that's great, but the low-light autofocus performance has been significantly improved. The A7S can focus down to -4EV with an f/2 lens, compared to just 0EV with an f/2.8 lens on the A7.
While it may resemble a still camera, the Sony A7S is packed with a suite of professional-level video recording features. Among its video amenities, the A7S includes ultra-high resolution 4K video, higher bitrate Full HD, and Picture Profile support (borrowed from Sony's professional camcorder line) with SLog2 gamma for very wide dynamic range and increased latitude for post-processing.
Check out our final verdict on Sony's unique 4K, high ISO mirrorless camera.
In the Box
The Sony A7S is sold body-only and the retail box contains the following items:
- Sony A7S body
- NP-FW50 Lithium-Ion Rechargeable Battery (1020mAh)
- AC-UB10 AC Adapter
- Shoulder Strap
- Body Cap
- Hot Shoe Cover
- Eyepiece Cup
- Micro USB Cable
- PlayMemories Home App
- Image Data Converter Version 4 Software
- Limited 1-year Warranty
- Large capacity SDHC/SDXC memory card. 16GB Class 10 should be a minimum (SDXC memory card required for XAVC S video format.)
- Sony FE-mount lens: FE 24-70mm f/4 Zeiss or FE 35mm f/2.8 Zeiss
- Extra NP-FW50 Lithium-Ion Rechargeable Battery (1020mAh) (~US$50)
- Sony Vertical Battery Grip for Alpha a7/a7R/a7S Digital Camera (~US$298)
- Sony HVL-F20M External Flash (~US$148)
- External Shotgun Microphone
- External 4K Recorder necessary for 4K video capture
- Small/Medium Carrying Bag
Note: For details, test results, and analysis of the many tests done with this camera, please click on the tabs at the beginning of the review or below.
1 $300 Adorama Gift Certificate
2 $200 Adorama Gift Certificate
3 $100 Adorama Gift Certificate