Sony a7R III announced – will it trump the new Nikon D850 dSLR? Features side by side

Written by Gary on October 25th, 2017

Sony have just announced their new flagship high resolution mirrorless full frame camera – the Sony a7R III.

The camera and sensor are much the same as it’s predecessor, but almost every area has been substantially improved with Sony addressing most of the weaknesses to such an extent that it may limit the sales of its sports/wildlife mirrorless camera, the new Sony a9, and may well convert many potential Nikon D850 dSLR buyers over to the Sony mirrorless world.

The main improvements over the Sony a7R II:

  • same sensor but 1EV more dynamic range at low ISO due to a gapless on-chip lens design and anti-reflective sensor coating and improved circuitry and processing
  • processes images 1.8 times faster
  • adds 425 CDAF points instead of 25, giving 68% of frame coverage instead of 45% coverage
  • AF twice as fast and extends to low light of -3EV
  • “Additional improvements in focusing flexibility include AF availability in Focus Magnifier mode, focal-plane phase-detection AF support when using A-mount lenses, an ‘AF On’ button, a multi-selector or ‘joystick’ for moving focusing points quickly, flexible touch focus functionality and much more,”
  • IBIS improved to “5.5EV”
  • 10fps burst rate instead of only 5fps in either mechanical or silent electronic mode but need to drop to 8fps for continuous live view
  • better mirror shock handling and better shutter shock handling
  • improved EVF and rear screen
  • adds “Pixel Shift Multi Shooting” similar to HiRes mode of Olympus OM-D cameras but delivering 4 pixel shifted RAW images covering 169mp which outputs to a single 42mp RAW with better colour fidelity and texture reproduction than a single shot (ie. much less moire)
  • adds the a9’s touchscreen focus point control and multi-selector joystick on the back of the body in place of the button-style directional pad as well as anti-flicker ability, a 2nd card slot
  • 120fps 1080 HD mode
  • USB 3.1
  • larger grip and battery 2.2x longer lasting (same as the Sony a9 full frame mirrorless camera)

Why would one consider a Sony a7R III instead of a Nikon D850?

  • amazingly good eye AF tracking
  • far more AF points and good frame coverage (although no where near as good as 98% coverage of the Sony a9)
  • in-camera 5 axis image stabilizer which will work on most lenses and potentially give 5.5EV benefit – now that is almost as good as the Olympus system!
  • awesome video features which on paper seem to trump the Nikon D850 capabilities, but probably won’t be as good as a Panasonic GH-5 as the 4K video has been crippled to only 8bit 100Mbps IPB, not 10 bit 400Mbit All-I as with the GH-5, while for run and gun work, the image stabilisation of the Olympus OM-D E-M1 II or the GH-5 would probably make these a better choice.
  • much better WiFi tethering (the Nikon only has suboptimal Bluetooth tethering)
  • Pixel Shift mode for minimal moire, improved image detail and color rendition
  • ability to have relatively fast AF with Canon EF mount lenses
  • ability to use a range of lenses not just Nikon mount lenses, and have them image stabilised
  • the many advantages of mirrorless technology

Head to head specs comparison:

The Sony a7RII and the Nikon D850 have many features which are similar, such as:

  • price – both are around $US3200
  • high resolution sensor without an anti-alias filter – 42.4mp for the Sony and 45.7mp for the Nikon
  • high dynamic range imagery
  • hotshoe, PC sync port and flash sync of 1/250th sec, with radio remote TTL and HSS options available (eg. Godox)
  • shutter speed 30sec – 1/8000th sec plus BULB
  • ISO range roughly similar
  • +/- 5EV exposure bracketing
  • silent mode
  • 4K video as well as 1080HD video, although the Sony has far more high end options and better IS and C-AF
  • dual SD card slots
  • weathersealed
  • reasonable battery life although the Nikon wins out easily here
  • Nikon has better ergonomics but the Sony has better manual focus capabilities
Sony a7R II Sony a7R III Nikon D850
in-camera IS “4EV” “5.5EV” NONE
Eye AF good excellent OK, limited area
AF points 399PDAF to -2EV/25CDAF 399PDAF to -3EV/425CDAF 153PDAF, one to -4EV/?CDAF
C-AF tracking poor excellent excellent, but POOR during Live View/Movie
metering ?1200 zone 1200 zone 180,000 RGB sensor
burst speed with C-AF 5fps 10fps 28 RAW / 76 compressed RAW 6fps 51 RAW (up to 9fps w/o CAF)
rear touch screen AF pad no Yes Yes
120fps 1080HD video no 100Mbps ?27Mbps
weight 625g 657g 1005g
special features Pixel Shift mode Focus shift mode, Native AWB; optional small, medium or large RAW modes


Both the Sony a7R III and the Nikon D850 are amazing cameras which will address most needs, albeit at a price and weight of the lens system. If Sony has substantially improved the ergonomics over my Sony a7II, then this evolution will be an extremely popular camera indeed, but personally, the Olympus OM-D E-M1 II is much more fun and much less of a burden while being more affordable when you factor in the cost and weight of the lenses.

I am envious though of how well the Eye AF appears to work – despite Olympus introducing this technology, it would seem that Sony has substantially improved upon the tracking capability. – I am sure Olympus will be addressing this soon.


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