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|