SONY A7 R III
Delivers Both Power And Glory
Sony reinforces its pro camera aspirations with the third-generation A7R mirrorless body which now not only delivers high res, but also high speed. 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 capture, and 28 frames when shooting uncompressed RAW files. The camera now has dual memory card slots – one exclusive to the SD format and the other compatible with both SD and MemoryStick Duo devices. As on the A9, only the former is UHS-II speed compatible while the latter is restricted to UHS-I. The file management options are simultaneous recording to both cards (either stills or video clips), split JPEG and RAW, or split stills and movie clips, copying and automatic overflow.
Pumping Pixels
Sony has championed in-body image stabilisation since its first foray into D-SLRs (actually inherited from Konica Minolta), but it wasn’t provided on the first A7 bodies because of internal space issues. The A7R III has the latest version which provides five-axis correction and for up to 5.5 stops. Much greater precision in the control of the sensor-shift enables Sony to offer a multi-shot pixel-shift function similar to those from Olympus, Pentax and, most recently, Panasonic.
Sony calls its function “Pixel Shift Multi Shooting” and it captures four images – shifted by one pixel left, right, up and down – which, when combined, are effectively 169.9 megapixels in resolution – although the image size is still actually 42.4 MP – with full RGGB colour captured at each pixel point. Consequently, both the level of detailing and the colour reproduction are greatly enhanced, but the downside with the A7R III’s function is that the four images are only captured as uncompressed RAW files and so can’t be combined incamera. This has to be done later using Sony’s new Imaging Edge software, which is available as a free download. Additionally, there’s no correction for any movement at all so the subject has to be completely stationary (as has the camera). Interestingly, though, the interval between each frame can be varied between one and 30 seconds – presumably primarily to allow any vibrations to fully die away, but it could make for some very interesting effects.
The A7R III is very well connected with a flash hotshoe – Sony’s ‘Multi Interface’ Shoe to be precise – a PC flash terminal (for the first time on an A7 series model), both micro USB 2.0 and Type C USB 3.1 Gen. 1 ports (the latter enabling tethered operations and in-camera battery charging), plus both a stereo audio input and output (3.5 mm minijacks). Connectivity is via WiFi with NFC and Bluetooth LE. The battery is the higher-capacity NP-FX100 2280 mAh lithium-ion pack as is used in the A9 and, consequently, the A7R III can be fitted with the same optional battery grip, the VG-C3EM. Sony quotes 530 shots from a single charge when using the EVF which is very good indeed. And, although the battery pack is also physically bigger than previously, Sony has been able to keep the camera’s external dimensions pretty much the same as those of the A7R II.
“Pixel Shift Multi Shooting captures four images – shifted by one pixel left, right, up and down – which, when combined, are effectively 169.9 megapixels in resolution.”