What is the Sony A7 III?

Announced on 27th February 2018, the Sony A7 III is a full-frame mirrorless camera and the replacement to the Sony A7 II. It’s designed to be a general-purpose camera and is aimed at experienced enthusiast photographers. Sony already has high-end all-rounder, the A9, but at over £4,000/$4,000 it’s out of reach for most enthusiast photographers.

The Sony A7 III price tag is half the cost of the A9 and it sits between the high-resolution Sony A7R III and the video-centric A7S II as the more affordable option.  Like its predecessor, the A7 III has a 24Mp, sensor but according to Sony it’s a new chip.

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Sony has stuck with 24Mp for the A7 III and on the basis of one of our recent Twitter polls, I think that will be a popular decision giving a nice balance between file size and detail capture (and noise control). 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, but there is a front-end LSI which Sony says doubles the readout speed from the sensor. According to Sony, this results in the focusing in low light being almost twice the speed of the A7 II in low light and the focus tracking is twice as fast.

The sensor and processing engine enable an overall sensitivity range of ISO 50-204,800, indicating 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 and is claimed to give a 5EV extension in the hand-holdable shutter speed.

Sony Alpha A7 III Review

Improved Autofocusing

The Sony A9’s autofocus (AF) system is phenomenal and 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, making 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.

Continuous Shooting

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 at this rate with the A7 III, if you want a continuous live view feed the rate can be dropped to 8fps.

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, so the camera can be made silent if necessary.

4K Video

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 so 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.

Sony Alpha A7 III Review


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.

Key Specifications

 Sony Alpha 7 III
Camera typeCSC
Date announced27th February 2018
Price at launch£2000/$1,998 (body only), £2,500/$2,198 with 28-70mm lens
SensorFull-frame (35.9 x 24mm)
Effective pixel count24.2Mp
Lens/MountE (FE)
ProcessorBionz X
Sensitivity rangeISO 50-204,800
Reflex AF systemN/A
Live View AF system693-point wide area phase detection AF
Max shooting rate10fps with full AF and metering
Max video resolution4K (3840 x 2160)
StorageDual card slots, Slot 1: SD(UHS-I/II compliant), Slot 2: Memory Stick Duo/SD(UHS-I)
Viewfinder0.5-inch OLED with 2,359,296 dots
ScreenTilting 3-inch Touchscreen with 921,600 dots
Dimensions126.9 x 95.6 x 73.7mm
Weight650g with battery and card

Sony Alpha A7 III Review: Product shot


Review Date
Reviewed Item
Sony Alpha A7 III