Sony has launched a new version of its entry-level A7 series full-frame mirrorless camera. The A7 III boasts improved image quality, better autofocus, high-speed continuous shooting and a host of other improvements.
This brings the total number of A7 models to eight. They split into three series. There are three A7R models designed primarily for high resolution, and the latest is the A7R III. There’s also a somewhat neglected 12-megapixel high-sensitivity video-orientated A7S model, still at version II, and there’s this, the all-round bread-and-butter A7 – though there’s nothing basic about this A7 III’s specifications.
The sensor resolution remains the same as the previous A7 II’s, at 24 megapixels, but the sensor has a back-illuminated design for greater sensitivity and is teamed up with a new front-end LSI and uprated BIONZ C processor to double the sensor readout speed and deliver a 1.8x improvement in image processing speed. The practical upshot is a greater sensitivity range, improved image quality and 10fps continuous shooting capability.
The ISO range now goes from 100-51,200, expandable to ISO 50-204,800, and Sony claims the new camera brings a 1.5-stop improvement in image quality – which we take to mean that it offers the same quality at ISO settings 1.5 times higher than on the A7 II.
Sony also claims 15 stops of dynamic range at lower ISO settings which, if it can be achieved by regular photographers outside of Sony’s test conditions, could match the dynamic range of professional medium format cameras.
The autofocus system is considerably more advanced too, and we’re told it’s taken from Sony’s flagship sports/action camera, the Sony A9. It incorporates 693 phase detection AF points covering 93% of the image area and 425 contrast AF points. That’s way higher in terms of AF points and frame coverage than any rival DSLR, though on-sensor AF systems have yet to prove themselves conclusively superior to high-end DSLRs for subject-tracking.
The Sony A7 III will have considerably appeal for fans of sports photography and not just because of its sophisticated AF system. It also offers continuous shooting at 10fps in either mechanical or silent electronic shutter mode, capturing up to 177 JPEGs or 89 compressed RAW files in a burst. This does drop to 8fps if you use the camera’s ‘live view’ mode, which sacrifices 2fps frame rate for a more responsive viewfinder image and smoother and easier subject tracking.
Like other new Sony A7 cameras, the A7 III incorporates Sony’s in-body 5-axis image stabilisation which, the company claims, offers 5 stops of compensation.
Users also get the kind of sophisticated 4K video features we now expect from Sony. The A7 III uses the full width of the frame to capture video, so there are no annoying crop factors to take into account when choosing lenses, and there’s no pixel binning – the camera captures ‘oversampled’ video at a higher resolution then downsamples it to 4K resolution to produce the maximum possible quality.
Pro video shooters can use the camera’s HLG (Hybrid Log-Gamma) for instant HDR playback on compatible HDR (HLG) compatible TVs, and there are S-Log2 and S-Log3 profiles for those who want to grade their video carefully later. The A7 III can also shoot full HD video at up to 120fps for 4x or 5x slow motion in full HD, with AF tracking while filming.
And Sony fans will be pleased to hear Sony has used its latest NP-FZ100 battery, which delivers 2.2x the life of the NP-FW50 used in the A7 II, and has a CIPA-tested battery life of 710 shots. That’s not much by DSLR standards but a huge step forward for a mirrorless camera.
Designed to cater for all users, from enthusiasts to professionals, the A7 III goes on sale in March 2018 for £2,000/€2,300 body only or £2,200/€2,500 in a kit with the Sony SEL2870 (28-70mm) lens.