Results Driven SONY A7R III
There’s been a tradition in pro-level D-SLRs of having a sports model and a studio model. High speed or high resolution. While the Nikon D850 – with a shade under 47 megapixels on tap and a top shooting speed of 7.0 fps (9.0 fps with the optional battery grip) – is blurring the boundaries a little bit, it’s still largely the case and Sony is adopting the same strategy with its top-end mirrorless cameras.
The A9 is first and foremost a sports and action camera – with the more rugged build that goes with this territory – while the A7R III is aimed squarely at users who want as much image quality as possible, with a 10 fps continuous shooting speed thrown in for good measure. What’s more, this is still with continuous autofocusing and exposure adjustment (and regardless of whether the focal plane shutter or sensor shutter is used). If you want continuous live view framing (i.e. with no black-outs) then the top speed drops to 8.0 fps, which is still faster than the D850 (and here the between-the-frames interruptions are unavoidable). There’s not much in the pricing (except if you factor in the D850’s fairly expensive optional grip which is needed to get 9.0 fps), so this is perhaps the most direct contest there’s been in the pro sector between mirrorless and D-SLR.
The A7R III inherits the Mark II model’s ‘Exmor R’ back-illuminated CMOS sensor which has an effective pixel count of 42.3 million, but it’s mated with an updated version of Sony’s ‘Bionz X’ high-speed processor and a new front-end LSI, which deliver quite a few improvements including a higher signal-to-noise ratio. This, in turn, delivers a dynamic range expanded to a massive 15 stops – this is medium format camera territory – and an increased sensitivity range equivalent to ISO 100 to 32,000 with expansions to ISO 50 and 102,400. As before, an optical low-pass filter is omitted to optimise the resolution. JPEGs can be captured in three sizes and three compression levels, along with the option of 3:2 or 16:9 aspect ratios and the smaller ‘APS-C’ format (which gives an image size of 18 megapixels). RAW files are now recorded with 14-bit RGB colour and the choice of uncompressed or compressed formats (but it drops back to 12-bit colour in the higher speed continuous modes). Burst depths are quoted as 76 frames with both JPEG/large/extra-fine or compressed RAW
