What is the Sony A7 III?
Announced on 27th February 2018, the Sony Alpha 7 III is more commonly known as the A7 III. It’s a full-frame mirrorless camera and the replacement to the Sony A7 II. It also has a lot to offer enthusiast photographers as a general-purpose camera.
Sitting between the high-resolution Sony A7R III and the video-centric A7S II as the more affordable option, the Sony A7 III’s price tag is also half that of the A9, the company’s pro-level all-rounder. However, it has quite a lot in common with the A9, not least the autofocusing system. In this review, I’ll take a detailed look at all the key aspects of the A7 III’s performance.
Follow this link to see our AF Testing Page.
Sony has stuck with a 24Mp sensor for the A7 III. On the basis of one of our recent Twitter polls, I think this will be a popular decision. It gives a nice balance between file size and detail capture. It also maintains the separation between the A7 Mark III and the A7R Mark III.
Although the sensor is backside-illuminated (BSI), it’s not the same sensor as is in the A9. However, there is a front-end LSI which Sony says doubles the readout speed from the A7 III’s sensor. According to Sony, this results in the focusing in low light being almost twice the speed of the A7 II’s. In addition, the focus tracking is twice as fast.
The sensor and processing engine enable an overall sensitivity range of ISO 50-204,800. That indicates that the A7 III should perform well in low light. In fact, Sony is claiming a 1.5EV improvement in image quality overall.
Sony’s 5-axis optical in-body image stabilisation is on hand. It’s claimed to give a 5EV extension in the hand-holdable shutter speed.
The Sony A9’s autofocus (AF) system is phenomenal. While the A7 III doesn’t have exactly the same system (that would require the same sensor), it has the same 693-point phase detection points and 425 contrast AF points.
These points cover 93% of the imaging area. This makes it easier than with the A7 II to track moving subjects. In addition, the system is sensitive down to -3EV, which means it should be effective in low light.
There’s also Sony’s Eye AF mode that helps you target the most important part of a portrait subject.
Sony has given the A7 III a maximum continuous shooting rate of 10fps. As with the A7R III when it shoots at 10fps, there is a brief blackout with the A7 III. Dropping the rate to 8fps gives a continuous live view feed.
With a fast card installed, the A7 III can shoot at 10fps for 177 Standard jpeg images, 89 compressed raw images or 40 uncompressed raw images. Furthermore, it’s possible to shoot at 10fps using the mechanical or the electronic shutter. This means you can shoot silently at 10fps if necessary.
The A7 III is capable of recording 4K (3840 x 2160) footage to a memory card at 30p/25p and 60Mbps or 100Mbsp. There’s also S-Log2 and S-Log3 available for recording flat footage ready for grading, and a Hybrid Log-Gamma (HLG) picture profile is provided for displaying video direct from the camera on HDR (HLG) compatible televisions.
When the camera is set to record 4K video it uses full pixel readout without pixel binning. This means it gathers around 2.4x as much data as is needed for 4K movies. It then oversamples the files to produce 4K footage with better depth and dynamic range.
There’s also a Zebra display, Gamma Display assist and proxy recording.
In addition, Full HD footage can be recorded at up to 120/100p (NTSC/PAL) for slow-motion playback.
One of the issues for the Mark I and Mark II A7-series cameras is low battery life. Sony addressed this for the A9 and A7R III with the NP-FZ100 battery. This battery has also been used in the A7 III and it has a claimed life of 710 shots when the screen is used to compose images.
|Sony Alpha 7 III|
|Date announced||27th February 2018|
|Price at launch||£2000/$1,998 (body only), £2,500/$2,198 with 28-70mm lens|
|Sensor||Full-frame (35.9 x 24mm)|
|Effective pixel count||24.2Mp|
|Sensitivity range||ISO 50-204,800|
|Reflex AF system||N/A|
|Live View AF system||693-point wide area phase detection AF|
|Max shooting rate||10fps with full AF and metering|
|Max video resolution||4K (3840 x 2160)|
|Storage||Dual card slots, Slot 1: SD(UHS-I/II compliant), Slot 2: Memory Stick Duo/SD(UHS-I)|
|Viewfinder||0.5-inch OLED with 2,359,296 dots|
|Screen||Tilting 3-inch Touchscreen with 921,600 dots|
|Dimensions||126.9 x 95.6 x 73.7mm|
|Weight||650g with battery and card|
Build and Handling
As far as I can tell, the Sony A7 III has the same body shape as the A7R III. It’s small for a full-frame camera, but has a decent grip on the front and a small but pronounced thumb ridge on the back. Together, these grips and their textured coating help the camera stick in your hand while you’re shooting.
It’s good to know that the camera is dust and moisture resistant.
I like the physical control arrangement of the A7 II with two exceptions, the location of the video activation button and the method of autofocus point selection. Happily, Sony has addressed both of these issues with the A7 III.
The video record button, which is on a corner of the body on the A7 II has been moved to the right of the viewfinder on the A7 III. That means it’s within easy reach of your right thumb and it’s far easier to operate it without making the camera wobble.
Sony introduced a mini-joystick style controller for setting the AF point with the A9 and it continued on to the A7R Mark 3. It has also made it on to the A7 Mark 3.
In another change from the Mark II, the A7 Mark III has an AF-On button on its back, just to the side of the thumb rest.
In case you haven’t guessed, I’m a fan of touchscreens. They make things like setting the AF point, making menu selections and setting adjustments more intuitive.
Sony has given the A7 III a touchscreen, but as on the A7R III and A9, it hasn’t gone the whole hog. You can’t tap on the options in the main or function menus to make settings changes for instance. However, you can use it for setting the AF point, even when you’re looking in the viewfinder if you like. And you can use it to zoom quickly into images to check sharpness.
I’m still keeping my fingers crossed for a firmware upgrade to increase the level of touch-control.
Viewfinder and Screen
The A7 III has a 0.5-inch OLED electronic viewfinder that gives a good clear view of the scene. That’s about as big as you want a screen so close to your eye because I find I have to move my eye to check the edges.
It would be nice if Sony could make the active AF point a bit more visible, perhaps by making it red. The black marker can be quite hard to see at times.
It’s good to see that the A7 III has a ‘My Menu’ option to which you can assign up to 30 menu items for quicker access. This is a very useful addition given the length and complexity of the camera’s menu.
Also, 11 of the buttons on the A7 III can be customised and there’s a total of 81 functions available for them.
The Sony A7 III is an impressive all-rounder camera.
I don’t think its low light autofocusing is quite as good as the Nikon D850, but it’s good. I was able to photograph a pair of dancers in a dimly lit room filled with smoke and the low contrast didn’t cause much in the way of problems.
Of course, one issue is selecting the right focusing mode of the shooting situation. In some situations, for example with a relatively uncluttered or motionless background, Wide Focus area is a great choice because the camera latches onto a subject that moves randomly with more success than when you try to follow it with a small spot in the viewfinder.
Similarly, Expand Flexible Spot allows you to target an area and then the camera follows it, but it can sometimes jump to a different part of the scene.
Eye AF, which by default is assigned to the Center button can be extremely useful, especially as it works in continuous focusing mode. I found it very helpful when shooting portraits or photographing the dancers, but it doesn’t always spot the eyes so you have to be ready to react.
With a resolution of 24Mp, the A7 III isn’t going to match the 42Mp A7R III for detail, but for much of its native sensitivity (ISO) range, it captures a high level of detail.
Even images captured at ISO 51,200 look good. The jpegs have a slight texture visible at 100% and show some signs of noise reduction, but they’re not objectionable. The raw files give you the option to avoid this noise reduction so you can have slightly more textured images with more detail.
The A7 III has a maximum sensitivity setting of ISO 204,800. Which although we’ve seen before, is a crazily high setting that allows photographs to be taken in very gloomy conditions. However, that setting is an expansion setting for a good reason. At that value, although I’ve seen worse, the images can suffer from false colour and noise. They could still be usable for news reporting or evidence gathering – or those situations when you just need an image.
Exposure and Colour
The A7 III’s viewfinder and screen can display the image as it will be captured so you can adjust the exposure before taking the shot. I found myself adjusting the exposure compensation dial quite a bit during my time with it at the press event. I’ll look into this in more detail when I have longer with the camera.
In its auto white balance setting the A7 III’s shots sometimes vary in colour a little depending upon the image composition. It’s not a dramatic shift in colour, but when the images are side by side it’s noticeable. For this reason, I usually either use a preset white balance or a Custom value that I set manually.
The video quality from the A7 III is also very high. As you’d expect the exposure, white balance and colour are the same as the stills. Details also look good, while noise is controlled well.
The fast readout speed means that rolling shutter isn’t a major issue, but the ‘jello effect’ isn’t controlled quite as well as by the Sony A9.
Overall, it’s capable of producing high-end results that make it a good choice for anyone who wants to shootstills and video in equal measure.
The autofocus (AF) system is a key selling point of the A7 III so I’ve spent quite a bit of time looking at its performance. Some of the first images I shot with it were of my dog playing fetch.
I used the Sony Carl Zeiss Vario-Tessar FE 24-70mmf/4.0 ZA OSS lens, at first keeping the AF setting in their default arrangements:
AF Tracking Sensitivity at 3(Standard)
Priority Set in AF-C: Balanced Emphasis
But then switching to:
AF Tracking Sensitivity at 5(Responsive)
Priority Set in AF-C: AF
With focusing set to Continuous AF (AF-C) and the drive mode set to Continuous Shooting: Hi+. This sets the camera to shoot at 10fps, the fastest rate available with the A7 III.
Luckily for me, Otto is obsessed with chasing balls, so armed with a launcher and a couple of balls, I set him in motion, taking photographs as he ran back to me ready for the next ball to be thrown.
Focus Area Wide
I spent some of the time with the camera set to the Wide Focus Area. When this mode is selected the camera uses all of the available focus points to detect the subject and focus on it. As I looked through the viewfinder I could see that on the vast majority of occasions the camera was managing to locate Otto in the landscape and was following him well.
As I found with the Sony A9, the A7 III’s AF-C system sometimes gets a bit fidgety when the subject isn’t moving, but when it is, it usually latches on quickly. You can see this as green squares appear over your subject and follow it around the frame.
Focus Area Flexible Spot
After several runs with the A7 III set to Focus Area Wide, I switched to Lock-on AF: Expand Flexible Spot S (Small) or M (Medium). In this mode you can choose the starting point for the AF and then the camera tracks the subject around the frame. It’s a very convenient option for a variety of subjects.
I generally find it easier to move the AF point to where I want it to be with my left thumb on the screen with the Touch Panel+Pad activated.
Again in the majority of cases, the green squares stayed over Otto’s head as he ran towards me.
Sony A7 III Autofocus Test Results
After downloading all the images, I checked them at 100% on my computer screen. This reveals that many of them are sharp with the focus point where I want it. However, when theAF Tracking Sensitivity was set to 3(Standard) there are lots where to focus is on Otto’s shoulder or the end of his body rather than his head.
The focusing system seems to have struggled the most when Otto was close to the camera but not closer than the nearest focusing point. At relatively close quarters, there’s greater chance of missing the focus because small movements have a more significant impact.
Using the Priority Set in AF-C: AF option reduced the number of failures and switching the AF Tracking Sensitivity to 5 the maximum boosted the success rate significantly.
There were a few occasions when the AF system moved the active points away from Otto, as I was shooting in a meadow of tall grass it’s possible that something got in the way, but it predominantly got the point in the right area and got his face sharp.
Sony A7 III Autofocus Test Images
A camera’s dynamic range is a measure of the range of tones that it is able to capture in a single image. A camera with a low dynamic range produces images that have dense shadows with little detail and the brightest areas, the highlights, burn out easily.
Conversely, a camera with a wide dynamic range captures images that lots of tones between the extremes of white and black.
Having the ability to capture lots of tones means that a camera reproduces tonal gradations well, so there’s no stepping or banding where there should be a smooth transition from one shade to another.
Sony claims that the A7III’s 14-bit raw files have a 15-stop, or 15EV, dynamic range. That’s a very high value on a par with what our eyes can see. It’s also beyond what the average computer monitor or printer can replicate.
However, capturing images with wide dynamic range allows you to make adjustments to images so they look as you want them to on screen or in print.
Sony A7 III Dynamic Range in Practice
After shooting in a range of conditions with the A7III, it’s clear that it does have an impressively high dynamic range. A little of the tonal range has been a lost in the images below, but they illustrate the point.
The high contrast scene below was shot using exposure settings that avoided any sign of Zebras with the Zebra Level set to 100+.
This meant reducing the exposure below that recommended by the camera, but the darkest parts still have a good range of tones.
Boosting the Shadows slider in Adobe Camera Raw (ACR) to 100 shows the degree of information available in the darkest areas.
However, producing a more natural, attractive image that better reflects the scene requires a lighter touch with the controls.
This scene was exposed using the settings recommended by the A7III. Unsurprisingly, given the bright scene in the window, the boy running towards the window looks very dark.
Boosting the exposure by 4.75EV in ACR reveals there’s plenty of colour visible in the darker parts of the image, and although some noise has crept in and the boy is out of focus, there is also detail visible in his clothes.
More subtle use of the ACR controls produces a better balance of exposure.
I dramatically underexposed this high contrast scene to record the person crossing the bridge as a silhouette and to get a deep blue sky.
Boosting the exposure to its maximum value of +5EV in ACR reveals that there’s a lot of information available in the shadows, but it’s pushing this image a bit too far.
I got a better, more natural looking result with the exposure set to +3.5EV.
However, below is how I envisaged the image when I shot it. The wide dynamic range has enabled detail to be revealed in the darkest parts of the scene and the end result is a dramatic image.
The Sony A7III has an impressively wide dynamic range that enables it to capture images that look natural.
It also means its raw files have excellent latitude. You won’t find the highlights burning out quickly and the shadows can be brightened post-capture if necessary.
In some instances, it’s possible to brighten the 14-but raw files by as much as 5EV. But 3.5-4EV is safer margin.
Sample Images from the Sony A7 III
Follow the link to browse and download full-resolution sample images
Sony Alpha A7 III Sample Images
Sony A7 III Review Sample Video
Shot for our Sony A7 III review in XAVC S 4K at 25p and 100Mbps
Shot with the Sony A7 III set to record XAVC S 4K at 25p and 100Mbps. For this video, I mounted the camera and the Zeiss 24-70mm f/4 lens (at 35mm) on the FeiyuTech A1000 stabilising gimbal.
Shot for our Sony A7 III review in XAVC S 4K at 25p and 100Mbps while travelling at approximately 30mph
Sony has improved the handling of the A7 III over the A7 II’s by the addition of the joystick control and touchscreen, as well as the better placement of the video record button. Overall, it feels more refined than its predecessor. It’s an excellent choice of camera for enthusiast photographers, perhaps even some pros.
If you’re interested in shooting sport, the A7 III’s autofocusing won’t disappoint. In addition, the silent shooting capability, wide dynamic range and good noise control make it appealing to social and wedding photographers. Although if you’re really serious about shooting weddings professionally, the Sony A9 is the camera to go for. It’s low-light AF system is excellent and its brilliant Eye AF makes life so much easier.
I like the A7 III a lot, but there are still areas that could be improved.
For example, it’s a real shame that Sony hasn’t made more use of the touch-control afforded by the screen. It could offer a quick and intuitive way to navigate the menu, but instead, its limits you to setting the AF point and zooming in and out of images. It seems like a waste of a great opportunity. I live in hope that Sony is going to reveal a firmware update.
Also, while its good that the A7 III has so many customisation options, some of them are confusing. And although Sony has made improvements, the extensive menu could still be better organised.
Despite these negative points, the Sony A7 III has an extensive features set and is a great all-rounder. Given that the Sony A7 III is pitched at the same audience as the 6D Mark II, Canon should be worried.
Should I buy the Sony A7 III?
The Sony a7 III is the full-frame camera that many people have been waiting for.
Its fast and silent shooting credentials, clever autofocusing and 4K video capability make it a great choice. It also produces high-quality results and Sony has a growing range of high-quality optics, adding to its appeal.
Bearing in mind its attractive price for a full-frame camera, it’s hard to justify not buying the A7 III!