Sony A7 III Review

March 26, 2018 | Mark Goldstein |


The Sony A7 III is a new "entry-level" 35mm full-frame compact system camera which, as you'll discover in our review, is far from being entry-level, despite being the cheapest model in the Sony full-frame line-up. The Sony A7 III has a 24.3 megapixel back-illuminated full-frame sensor with an optical low-pass filter, BIONZ X processor, expanded dynamic range of 15 stops at low sensitivity settings, dust/moisture-resistant magnesium alloy body, ISO range of 50-102400, hybrid auto focus system with 693-point phase detections points that cover 93% of the frame and 425 contrast-detection points, Eye AF in both AF-S and AF-C modes, 10fps burst shooting with full AF/AE tracking (up from 5fps on the A7 II), XGA OLED electronic viewfinder with 2.36m-dot resolution and 0.78x magnification, tiltable 3.0" 922k-dot rear LCD touchscreen, NFC, Wi-Fi and Bluetooth connectivity, UHD 4K movie recording with XAVC S and S-Log2/3 support, and greatly improved battery life.

The Sony A7 III is priced at around £1999 / $1999 body only or £2299 / $2299 with the Sony FE 28-70mm f3.5-5.6 OSS kit lens.

Ease of Use

In terms of its external design, the new Alpha A7 III camera doesn't really depart too much from either the previous A7 II model or the more expensive models currently in the range, the A7R III and the A9.

The aluminium bodied Sony A7 III is slightly bigger and heavier than the 3-year-old Mark II that it replaces, but it's still quite small and slender overall, measuring 26.9mm x 95.6mm x 73.7mm, and weighing 650g (almost 100g more than the A7 II) without a lens, battery and memory card fitted.

This increase in depth and weight is largely down to the much bigger battery and the subsequently larger handgrip to accomodate it. The larger capacity battery more than doubles the CIPA-rated battery life to 710 shots, the longest of any Sony Alpha camera, addressing one of the most common complaints about Sony's mirrorless camera range, namely the poor battery life. Subsequently the A7 III is slightly heavier then the Mark II version, but both easier to hold and capable of lasting for a full day's shooting on one battery, something that Sony shooters have long been wishing for.

The shutter release button sits in a logical position on top of the larger handgrip, with a command dial also conveniently located on the front. Also located on the front of the A7 III is the newly reinforced lens mount which has been further improved to better support heavy lenses, and a small porthole on the left for the self-timer/AF illuminator.

Sony A7 II
Front of the Sony A7 III

The A7 II's awkwardly positioned one-touch movie record button, which was previously located on the corner of the rear thumb-grip, has been moved directly to the right of the viewfinder, a much better location, while the C3 button is now on the rear-left of the camera.

Look under the memory card flap and you'll find not one, but two, SD card slots, although somewhat disappointingly only one of them supports the fastest UHS-II standard, a missed opportunity on such a fast shooting camera. Finally, Sony have als added both USB-2 and USB-C / 3 ports, the latter meaning that you can now power and tether the camera at the same time, a great boon for studio shooters, although it lacks the A7R III's PC Sync port.

The Sony A7 III features an in-body 5-axis image stabilization system to help prevent unwanted camera shake in low-light. It automatically corrects for pitch and yaw movement, plus horizontal shift, vertical shift and rotary motion (rolling) for both still images and movies. The A7 III offers an improved 5-stops of compensation, 1/2 stop more than the A7 II, which is very impressive considering that the A7 III has such a large sensor.

Furthermore, the use of an in-body system, rather than a lens-based system, ensures that the Alpha A7 III can stabilize all kinds of lenses, not just those with the FE designation, including E-mount lenses without Optical SteadyShot (OSS), A-mount lenses and even third party lenses mounted via the popular Sigma MC-11 or Metabones adapters. Note that lenses without any electronic contacts only benefit from three axes of compensation, and you also need to manually input which focal length you’re using to ensure that the stabilization works properly.

Sony A7 II
Rear of the Sony A7 III

On the top of the A7 III is a familiar external hotshoe, dubbed the Multi Interface Shoe, for attaching one of a range of accessories, including an external flash. As with the other Alpha cameras, thanks to its electronic front curtain shutter the A7 III has a sync speed of 1/250th sec, making it well suited to flash-based portrait photography, especially when used in conjunction with the amazing Eye-AF mode.

Completing the top of the A7 III is a second prominent dial for setting the Exposure Compensation and two small button marked with C1 and C2, which as the names suggest can be customised to access one of the camera's key controls. We wish Sony had made the EV button lockable, as its position on the corner of the camera meant that it was often inadvertently knocked into a different (unwanted) position when stored in a camera bag.

Just like the previous model, the A7 III uses a hybrid AF system which employs both phase-detection and contrast-based auto-focusing, but the number of AF points and the frame coverage have both been greatly increased. There are now 693 phase-detection points (up from 117) that cover 93% of the frame, plus 425 contrast-detection points (up from 25), and the AF system is subsequently twice as fast as the A7 II.

Sony A7 II
Top of the Sony A7 III

This is something that I definitely appreciated in the field, where the camera rarely if ever missed the moment because of an issue with the auto-focusing. It proved adept at both locking onto and tracking a moving subject, and excelled at portraits thanks to the dedicated Eye AF mode, which instantly recognises, locks onto and tracks a human eye in both the AF-S and AF-C focusing modes. In our tests this mode even worked impeccably with a lot of third-party lenses - we successful used an old Canon EF 24-105mm f/4 L lens with a Sigma MC-11 adapter to take great portraits of fast-moving children, all thanks to the Eye-AF mode, which never missed a beat.

The AF experience has been improved by the addition of a thumb-operated joystick to set the AF point, something that several rival cameras now offer and a much more intuitive method than using the navigation pad, as on the Mark II. Accompanying this is another addition in the form of a new AF-On button, which makes it a snip to back-button focus using your thumb rather than half-pressing the shutter button, a method that many photographers swear by. The main casualty of these changes is the loss of the A7 II's AF/MF switch, which you'll now need to set via the Function menu or the dedicated button on the lens (if there is one).

The other major speed increase offered by the Sony A7 III is its continuous shooting speed. The Mark II had a reasonable 5fps burst mode, but the new Mark III takes things to another level by offering 10fps burst shooting with Full AF/AE tracking for up to 177 JPEGs, 89 compressed RAW or 40 uncompressed RAW images in one high-speed burst, available with either the mechanical shutter or a completely silent electronic shutter. It can also shoot continuously at up to 8fps in live view mode, much like the A6500 camera.

Sony A7 II
Tilting LCD Screen

The A7 III features a very good, but not class-leading, electronic viewfinder. This is an XGA OLED electronic viewfinder with 2.36m-dot resolution and 0.78x magnification, which isn't quite as good as the viewfinder on the A7R III camera. Likewise, the LCD screen on the rear isn't quite as well-specced as the A7R II, either. It's the same 3-inch size and tilts in the same way as on the A7R III, but the resolution is lower at 922k-dots, rather than 1.44m. You'd probably be hard-pressed to notice either difference unless using the two cameras side-by-side, but they are two of the ways that Sony have managed to hit the A7 III's aggressive price-point.

The LCD screen is now also touch sensitive, which can be used for some elements of operation, including operating the auto-focus whilst looking through the EVF, a feature that we've seen on several other high-end mirrorless cameras recently. Unfortunately Sony have again stopped short of offering a full touchscreen experience - somewhat inexplicably, you can't use the menu system in this way, press the on-screen icons, or even scroll through images during playback, a la smartphones.

The Sony A7 III can shoot and record 4K video in multiple formats, including full-frame and the Super 35mm formats. It can output uncompressed UHD 4K, 3840 x 2160 pixel video (30p/24p/25p) at a 4:2:0 color depth to the inserted memory card or 4:2:2 over HDMI to compatible third party recorders.

Sony A7 II
The Sony A7 III In-hand

The A7 III supports the XAVC S format, which is based on the professional XAVC codec, and can record Full HD at 120fps at up to 100Mbps, which allows footage to be edited into 4x or 5x slow-motion files, with a new S&Q mode (Slow and Quick motion) on the shooting dial providing selectable frame rates ranging from 1fps to 120fps. A new HLG (Hybrid Log-Gamma) mode is available that supports an Instant HDR workflow, while both S-Log2 and S-Log3 are available for increased colour grading flexibility.

The A7 III uses the same recently revised menu system as the A7R III and A9, which is clearer and easier to navigate than on previous A7 cameras, although still frustratingly difficult to navigate though, with no less than 35 different screens of options.

As denoted by symbols on the side of the camera, the Sony A7 III is both wi-fi and NFC capable, and it also now offers location data acquisition via a Bluetooth connection to a compatible mobile device, allowing you to geo-tag your images.

It's not all good news on the connectivity front, though, as the A7 III no longer offers the PlayMemories app support that its predecessor, which amongst other things means that this new camera doesn't currently offer any time-lapse functionality, whereas the A7 II did. We hope that Sony will reinstate this and some of the other PlayMemories app functions via a future firmware upgrade.