Sony packs the new Alpha A7 III with its latest imaging tech

The Alpha A7 III is Sony's latest full-frame mirrorless camera, and sits at the bottom of its full-frame lineup below the 42.2MP Alpha A7R III and 20fps Alpha A9

It replaces the Alpha A7 II that was launched back in 2014, and Sony has lavished much of its latest tech on the Alpha A7 III, aiming to redefine what we should expect from an entry-level full-frame camera.

While the resolution remains the same, the new sensor in the Alpha A7 III features a back-illuminated design that delivers a much faster readout speed than the older model. Coupled with the latest BIONZ X image processor, the new A7 III is capable of shooting at 10fps (double that of the A7 II), with the option to use the silent shutter at this speed as well.

Not only that, but the buffer has also been greatly improved, and is now capable of shooting 177 consecutive JPEG images before the camera needs to take a breather, compared to 52 on the A7 II, while raw performance is still impressive at 89 shots.

The sensitivity range has also been greatly improved, now with an extended ISO ceiling of 204,800 – the same as the Alpha A9, and two stops better than the A7 II's 51,200 limit. Sony also reckons it's managed to achieve a dynamic range of 15 stops.

693-point AF system

We didn't expect to see this on Sony's 'basic' full-frame camera, but the Alpha A7 III gets the same 693-point AF system that's impressed us on the Alpha A9. It's a massive improvement over the 117-point arrangement on the Alpha A7 II, while the coverage also matches that of the A9 at 93%. Sony's clever Eye AF functionality also features, while the system is capable of focusing in light levels as low as -3EV. 

To help keep things steady, the Alpha A7 III gets Sony's latest 5-axis built-in image stabilization system, offering up to five stops of compensation. 

4K video

As you'd expect, the Alpha A7 III offers 4K video recording (3840 x 2160), using the full width of the camera's full-frame sensor and without pixel-binning. With a 6K readout, the Alpha A7 III collects 2.4x the amount of data required, with footage then oversampled to produce what Sony believes will be 4K footage with exceptional detail and depth.

As we've seen with the Alpha A7R III, the Alpha A7 III features a new HLG (Hybrid Log-Gamma) profile that supports an Instant HDR workflow, allowing HDR (HLG) compatible TVs to play back 4K HDR footage.

As well as this, both S-Log2 and S-Log3 are available for increased color grading, while if you want to shoot Full HD footage you can do so at up to 120fps.

Improved battery performance

One area where mirrorless cameras have struggled against their DSLR counterparts has been battery performance, so it's great to see the Alpha A7 III's battery rated for up to 710 shots – that's a huge improvement over the 350 shots of the Alpha A7 II, while it also has the edge on the Alpha A9's 480-shot battery life. 

The Alpha A7 III sports dual SD slots, with support in one slot for UHS-II type SD memory cards. There's now a dedicated AF-On button on the rear of the camera, and touchscreen functionality on the tilt-angle display. Proportionally the body is pretty much identical to that of the Alpha A7R III. 

The Alpha A7 III is expected to be available in March priced at $1,999 / £2,000 / AU$3,099 for the body only, and £2,200 with the 28-70mm f/3.5-5.6 standard zoom lens. US and Australian pricing for the lens kit is still to be confirmed.

Phil Hall

Phil Hall is an experienced writer and editor having worked on some of the largest photography magazines in the UK, and now edit the photography channel of TechRadar, the UK's biggest tech website and one of the largest in the world. He has also worked on numerous commercial projects, including working with manufacturers like Nikon and Fujifilm on bespoke printed and online camera guides, as well as writing technique blogs and copy for the John Lewis Technology guide.