Sony A7S III Review

Sony’s A7 series cameras come in three lines, the A7, A7R and the A7S. The A7 line, the most recent of which is the A7 III, is the all-rounder option whereas the A7R cameras like the Sony A7R IV are the high-resolution models. The A7S cameras are the most video-centric cameras and the Sony A7S III is the long-awaited update to the A7S II.

Like previous A7S models, the Sony A7S III has a full-frame sensor with 12.1 million effective pixels. Keeping the resolution down benefits its low-light capability by keeping noise levels down.

As well as a host of improvements to its video specification, the Sony A7S III introduces the highest-resolution electronic viewfinder we’ve seen to date and it’s the first Sony A7-series camera to feature a vari-angle screen. According to Sony, this is something that videographers and photographers have ‘demanded’.

Although Sony has stuck with the same resolution as the A7S II, the 12.1Mp full-frame CMOS sensor inside the Sony A7S III is new and has backside-illuminated (BSI) structure. Using this design enables the photosites to receive more light than a standard CMOS sensor, which means its low-light performances is boosted.

According to Sony, using a BSI design also doubles the readout speed which brings a range of performance enhancements.

Sony has also combined the new sensor with a new processing engine dubbed Bionz XR, which is said to enable up to 8x faster processing.

As well as boosting the low-light performance and enabling a sensitivity range of ISO 40-409,600 for video, using this sensor and processing engine combination enables the A7S III to capture video with up to 15 stops or more dynamic range at low ISO settings and in S-Log.

The dynamic range of the A7S III’s stills is claimed to be 14EV.

Also, thanks to the faster readout and processing, the A7S III is said to suffer from minimal rolling shutter (jello) effect.

4K Full-sensor readout

The headline video feature of the Sony a 7S III is that it can shoot 4K video at up to 120p and full HD footage at up to 240p, with full-sensor readout no pixel-binning and with the hybrid autofocus system in action.

There’s also 10-bit colour depth and 4:2:2 colour sampling available in all recording formats.

Sony has introduced new XAVC S-I 4K (All-Intra) and XAVC HS 4K (Long GOP) video formats and improved the XAVC S 4K (Long GOP) format for the A7S III.

Intra-frame recording is a compression procedure that captures more data but requires higher bit rates and therefore more uses storage capacity than Long GOP. It’s useful when you need the best quality 4K video recorded internally.

XAVC S-I 4K (All-I) can be used in normal recording at 50/25fps and 10bit 4:2:2 500Mbps and in S&Q (Slow and Quick) mode at 110/50/25/12/6/3/2/1fps at 25p (4x slow-mo)/50p and 10bit 4:2:2 250Mbps. It’s the S&Q options that make using a CFexpress card essential.

The bit rate in S&Q mode is 250Mbps which means the recorded bitrate/framerate is 10, much higher than in previous cameras. As a result, the in-camera slow and quick motion results should be much better than in the past.

It’s worth noting here that although (as usual) audio isn’t recorded in S&Q mode, the AF system can operate, which means there should be no problems tracking a fast-moving subject and creating a slow-motion video.

As well as recording to a UHS-II SD card or a CFexpress Type A card in the memory port, the A7S III can output 16-bit raw 4K 60p footage via its HDMI 2.1 connection to an Atomos Ninja V. It’s worth remembering here that 60p is the maximum framerate supported by HDMI 2.1.

Colour

As you’d expect, the A7S III has 10bit S-Log 2 and 3 available. According to Sony, in S-Log3 the results it produces match those from the Sony PXW-FX9.

Sony has been working on the colour science behind the A7S III’s S-Gamut3 and S-Gamut3.Cine gamuts and the camera is claimed to have much better colour saturation at high sensitivity (ISO) settings than the A7S II once the s709 LUT has been applied.

That’s great news for anyone wanting to grade their video, but Sony hasn’t ignored the requirements of less experienced videographers and those who need an ‘out of camera’ solution. Consequently, the A7S III has a total of 10 colour profiles, 4 of which are new (FL Film-like tone, IN Instant camera tone, VV2 Vivid tone with bright tone and SH Soft & Highkey).

There are also 8 image control parameters available for adjustment – saturation, contrast, shadow, highlight, fade, sharpness, sharpness range and clarity.

Autofocus

The Sony a 7S II has rather lacklustre autofocus performance, but Sony’s autofocus systems are now one of the best available in a mirrorless camera, if not any camera. I say one of the best as the Eye AF performance crown has been stolen by the Canon EOS R6 and Canon EOS R5 which have an uncanny ability to spot eyes in the frame – even animals eyes in video.

Anyway, it’s not really a surprise to see that Sony has given the A7S III a hybrid AF system with 759 phase-detection points and 425 contrast-detection points. Helpfully, the phase-detection points cover 92% of the sensor.

Further good news is that the real-time Eye AF system is also available and is said to be 30% better than previous systems. It also operates in both stills and video mode. It can be set to detect either human or animal eyes in stills mode and human eyes in video.

In addition, the AF system is claimed to be sensitive down to -6EV, which means it should be able to operate in the gloomy conditions that the A7S III is said to excel in.

Usually, with stills-shooting you want the autofocus system to be as fast as possible, but when you’re shooting video you often want smoother, slower transitions in focus. The A7S III has seven adjustment steps for AF for transition speed rather than five like the A7S II and the AF subject shift sensitivity can be adjusted across five steps.

I suspect that the A7S II is largely used in manual focus mode during video shooting, but the A7S III could well be the opposite as the AF system is likely to be very good.

Read our A7R IV review

Stabilisation

Like the A7S II, the Sony A7S III has 5-axis image stabilisation built-in. This is claimed to offer up to 5.5EV shutter speed compensation when shooting stills. It’s also possible to activate digital stabilisation if it’s required. This is called SteadyShot Active and as you’d expect, using it results in a slight crop being applied to the framing.

Still File Formats

While it is primarily aimed at videographers, the Sony AS III is still able to shoot stills and could appeal to photographers looking for a low-light camera.

As you’d expect, the A7S III can shoot raw and Jpeg images but Sony has also included the option to shoot 10-bit HEIF (High-efficiency file format) images. These files are the same size as Jpegs but they have more colour data which means they can have smoother gradations and are better able to withstand editing.

Dual Card Slots

Although the Sony A7S III has two SD-type card slots which are compatible with UHS-II media, the slots can also accept CFexpress Type A cards. These are smaller than the Type B cards we’ve seen in use to date, and they’re not quite as fast, but they’re fine for the A7S III’s 4K video-shooting capabilities.

It’s great to see that the memory card types can be mixed so if you only have one CFexpress card, you can pop an SD card in the other slot.

Read our Sony A7 III review

While it looks very similar to the A7R IV and A7 III, the A7S III is a little different because it has a variable screen (whoop!). It means it’s a millimetre or two larger here and there.

Sony has also upgraded the dust and weatherproofing to the same level as the A7R IV and A9 II.

Overall, the A7S III feels more robust than the previous generation camera. It feels more of a professional-level camera than the A7S II or A7R III and A7 III. I particularly like the grip which has a deep groove that’s perfectly positioned for accommodating the middle finger of your right hand when you’re holding the camera with your index finger on the shutter button.

On the back of the camera, there’s a small but well-shaped ridge that your thumb can brace against. Combined with the front grip, this makes the A7S III feel very secure in your hand when you’re holding it one-handed.

Feeling the heat

Mindful of the problems that heat can cause when shooting high-resolution video, the A7S III is said to be 5x more efficient than previous cameras and the heat-dissipating design enables 4K 60p video to be shot for up to an hour without problems – that’s something that the Canon R6 struggles with, I found it shuts down a few minutes into recording a second 30-minute clip at 25p.

Control Arrangement

The Sony A7 III and A7R IV have been around so long now that it’s easy to forget the handling updates that the Mark III cameras made over the Mark II versions. The A7S II still has the awkwardly placed via record button but thankfully that’s been resolved in the Mark III upgrade.

And let’s not forget that there is no mini-joystick on the back of the A7S II, that’s also been corrected with the Mark III camera. It’s quite a broad joystick with a coarse texture that gives good purchase.

Of course, the biggest handling change made by the A7S III is the introduction of a vari-angle screen. This is a first for a Sony A7 camera and one that I welcome wholeheartedly.

Further good news is that Sony has extended the use of touch control which is of course particularly useful with a video camera when you want to make silent settings adjustments. It’s even possible to navigate the main menu and make setting selections by touch on the screen.

Vari-angle screen

According to Sony, the 3-inch vari-angle screen wasn’t a request for the A7S III, it was a demand. It’s certainly something I’ve mentioned on many occasions.

In the past, the argument against one has been that a vari-angle hinge is less robust than a fixed screen and that ‘most dedicated videographers use an external monitor’. Those two points may still be true, but one of the key benefits of using a camera like the A7S III is its small size. If you start having to add an external monitor it makes it bigger and heavier.

Sony is also at pains to point out that the A7S III is for new videographers as well as experienced shooters and many of those people are unlikely to want to also lash out on a monitor.

It’s good to see that there’s an option to show a red outline around the on-screen image when the camera is recording. There are times when this is more useful than the usual flashing red dot.

Sony A7S III Menu

Sony has often received criticism for the complexity of its mirrorless cameras’ menus. Obviously, with such a feature-rich camera as the A7S III, there’s still going to be a long menu, however, Sony has given the matter some serious thought and the menu looks to be better laid out than on previous cameras with better grouping of key features.

Sony has arranged the menu tabs in a column on the left of the screen rather than across the top. These also colour-coded and the icons upgraded to make the whole thing look a little bit more 2020. To the right of the tabs, there’s a column of the various features listed within the selected tab and as you scroll down them, you see the options and settings available for each item. As I mentioned earlier, these can be selected with a tap or using the navigation controls.

Further good news is that there’s a dedicated menu for still and video shooting, which means you only see the options you need. It’s even possible to specify aspects such as the shutter speed, sensitivity (ISO), white balance and exposure compensation that are selected when you switch to video mode. That saves having to readjust everything when you change mode.

I’m very pleased to see that there are two Function (Fn) menus, one for stills and one for video. Both of these can be customised.

While the new menu arrangement is a big improvement that makes it easier to find the features you want, there are still a few issues. For example, when you’re selecting the settings for movie recording, there are some that aren’t available in certain modes and you find yourself hopping backwards and forwards. It would be nice to see a grid display or something similar that shows which frame rates are available with which file formats. The Canon EOS R6 and R5 do this very well.

There are also occasional warning displays that highlight an issue but don’t make it clear what the solution is, for example, when setting the file format in video mode to you see the message ‘A corresponding environment is required for playback of movies recorded in XAVC HS 4:2:2 10bit’. It would be helpful to know what that corresponding environment is.

Viewfinder

The Sony A7R IV has a 0.5 type 5.76million-dot OLED and it provides a very detailed, natural view of the scene with the camera settings applied. Stepping up to a 0.64-inch screen means you get a bigger view of the scene and the 9,437,184-dot resolution ensures that fine details are visible. However, moiré patterning is sometimes visible in areas with very fine repeating patterns, such as fabric, and some edges show a hint of chromatic aberration.

Battery Life

Battery consumption is often an issue with mirrorless cameras, the A7S III uses the Sony NP-FZ100 rechargeable battery which lasts for about 60% longer than the A7S II’s battery. It enables up to 95 minutes of video to be recorded instead of 60minutes with the A7S II and around 600 images to be captured (when the LCD is used) instead of 370.

It’s also possible to charge the battery or power the camera via a USB-C connection. In fact, charging via a USB connection speeds the charging by 3-4x.

While it is a very capable stills camera, most photographers are likely to be unimpressed with a pixel count of just 12 million. However, keeping the pixel count low enables each photosite on the sensor to be comparatively large and this helps to boost the A7S III’s low light performance. That could be attractive to a wedding photographer, for example, who wants to take advantage of the A7S III’s silent shooting and capture images in the low-light of a church, or a photojournalist.

Sony A7S III AF Performance

Of course, with a mirrorless camera, having larger pixels that gather more light doesn’t just benefit the image quality, the autofocus system is better able to detect a subject in gloomy conditions as well. And even in the dim conditions of a November woodland on an overcast day in the UK, the Sony A7S III has a high hit rate with a moving subject. It even coped well with my little dog running around in fallen leaves that are great camouflage for his brown fur.

With video in mind, the AF/MF section of the menu has an option to adjust the focusing speed to suit your subject. There are 7 AF Transitions Speed settings running from 1 (slow) to 7 (fast).

As with the stills, if you have a fast-moving subject and half-way decent light, with the correct setting the AF system can detect it and keep track of it. Alternatively, just tap on the screen over the subject and it will be tracked very effectively.

It’s also possible to change the AF Subject Shift Sensitivity and control the camera’s enthusiasm for sticking with a specific subject or tracking another. This can be adjusted across 5 settings and I mostly used it at 5, the most responsive. It’s something that I recommend testing with any subjects that you shoot on a regular basis until you find the one that works best for you.

The Eye AF is also dependable, but a shade behind that of the Canon EOS R6 and R5. It would also be nice to see Animal Eye AF in video mode.

Sony A7S III Image Quality

In stills and video mode, the Sony A7S III has a native sensitivity range of ISO ISO 80-102,400 with expansions settings pushing the range to 40-409,600. As usual, that upper range is best avoided unless it’s really important to get an image, perhaps for news reporting.

Images and video captured at ISO 409,600 have lots of noise visible, with blurry details and patches of false colour. However, the subject is recognisable, which is s step up from some other cameras at their very highest sensitivity setting. While the results have little aesthetic appeal, the stills and video could be of use for news reporting.

Drop down to ISO 102,400, the uppermost native sensitivity setting, and things improve a lot. However, I would aim to shoot at at least stop lower whenever possible as the noise is kept under much better control.

Image Stabilisation

There’s no question that the A7S II’s stabilisation is useful for stills and video shooting, and it’s worth switching it to the active mode for video, but it’s a stretch to call it gimbal-like. It’s handy for taking out those fine shakes and tremors that come with hand-holding a camera, but a gimbal like the Zhiyun Crane 2S is still a good call for run-and-gun video.

Colour and Exposure

Armed as it is with an accurate viewfinder and screen, plus zebra and live histogram views, there are few excuses for getting the exposure of video or stills wrong. On the whole, I found that the Multi Metering mode is a good default option and the exposure guides are useful keeping an eye on the highlights in case you need to use adjust the exposure, apply a little exposure compensation or tweak the variable ND setting.

Picking the white balance and Creative Look or Picture Profile to suit your scene or style is a creative decision, but in the default settings, the Sony A7S II produces attractive and natural colours. Should you prefer to extend the dynamic range and get the look you want in post-processing, there are the Log modes to get flatter footage from the camera.

This XAHV HS 4K 50p 200M 4:2:2 10bit video was shot hand-held with the FE 24-105mm f/4 G OSS lens mounted. The lens and camera stabilisation were both on, with Steadyshot set to Standard. The exposure was controlled manually while the white balance was switched between auto and Daylight. The autofocus was set to continuous in Zone AF mode with the Face/Eye Priority on and set to Human (although Animal doesn’t work in video mode).

The video below was shot on the Sony A7S III set to XAHV HS 4K 50p 200M 4:2:2 10bit with the FE 24-105mm f/4 G OSS lens mounted. The camera was mounted on a tripod at the start and then a Zhiyun Crane 2s for the moving shots. The exposure was controlled manually while the white balance was switched between auto, Daylight and Shade. The autofocus was set to continuous in Zone AF mode.

Follow the link to browse and download full-resolution images from the Sony A7S III

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Sony hasn’t gone for the head-turning 8K video resolution of the Canon EOS R5, but it makes some very attractive upgrades to the A7S II. The high-resolution viewfinder, vari-angle screen, re-thought menus and upgraded autofocus systems are of particular note along with the improvements to the noise control, colour and dynamic range.

The A7S III’s handling and control arrangement is a major improvement upon the A7S II, but it’s also much better than any of Sony’s other cameras. I’m keeping my fingers crossed that these changes are carried into the Sony A7 IV, which can’t be too far off now, and the A7R V when the Sony A7R IV’s retirement comes.

As good as the Sony A7S III is for experienced videographers, it’s good to see that it’s also capable of producing superb 4K video without using some of the advanced features. So if you don’t have an external monitor/recording device and you’re relatively new to grading Log files, you can still great great results.