Sony Alpha A7R III

The Alpha A7R III is Sony's latest high-resolution mirrorless camera, and an update of the excellent Alpha A7R II, which was responsible for tempting many a photographer away from the comfort of their Canon and Nikon DSLRs. 

This latest model looks to draw on many of the technologies used in the speed-orientated Sony Alpha A9, which is just as well, because with the likes of Nikon's brilliant D850 offering a tempting combination of high resolution and high performance the Alpha A7R II was beginning to look a little pedestrian. 

With some impressive boosts to performance, as well as tweaks to handling and the peace of mind of a five-year guarantee, could the new Alpha A7R III see even more secondhand Canon and Nikon DSLRs appearing on the shelves of camera stores as more photographers make the switch? 

Features

  • Full-frame stacked CMOS sensor, 42.2MP
  • 3,686K-dot electronic viewfinder with 100fps refresh rate
  • 3.0-inch tilt-angle screen, 1,440,000 dots

While many might have expected Sony to perhaps boost the amount of pixels to match or exceed DSLR rivals like the D850 and Canon EOS 5DS, it's actually opted to stick with the same count as the Alpha A7R II.

At the core of the A7R III then is a 42.2MP back-illuminated full-frame Exmor R CMOS sensor, although Sony has borrowed some of the innovations from the 24.2MP Alpha A9 and integrated them with this more densely populated chip. 

There are gapless microlenses and a new anti-flare coating for starters, while the Alpha A7R III features a new front-end LSI that almost doubles the readout speed of the sensor. It also takes advantage of the latest BIONZ X image processing engine, and combined, these enhancements deliver a boost in processing speeds of up to 1.8 times compared to the A7R II. 

Sony says the Alpha A7R III has a staggering 15-stop dynamic range at low sensitivity settings

The A7R III's sensitivity range remains unchanged (ISO50-102,400 at the camera's expanded setting), so those hoping for something to match the Nikon D850's expanded ISO32 setting may be a little disappointed. However, the new processing engine should be able to handle image noise better than its predecessor, while Sony also claims the Alpha A7R III will have a staggering 15-stop dynamic range at low sensitivity settings. 

The Alpha A7R III has the same electronic viewfinder (EVF) as the Alpha A9, with the Quad-VGA OLED EVF sporting a resolution of approximately 3,686k dots, and utilizing a Zeiss T* Coating to reduce reflections. On top of this, the A7R III supports a customizable frame rate for the EVF, with options of either 60fps or 120fps, again matching the 120fps offered by the A9. 

Along with the EVF, the rear tilt-angle display has also been upgraded over the outgoing model; it now has a resolution of 1.44 million dots, and just as we've seen with recent models like the RX10 IV, offers touchscreen functionality. 

Also as in the Alpha A9, Sony has shunned the XQD card format (even though it's now the sole manufacturer of that format), instead opting for dual SD card slots on the Alpha A7R III, with only one of those supporting UHS-II type cards.

The Alpha A7R III offers 4K (3840 x 2160 pixels) video capture, with the option to use either the full width of the sensor or Super 35mm format mode, with the latter using the full pixel readout without pixel binning to collect 5K of information, and oversampling this to produce what promises to be even crisper footage. 

As well as this, the Alpha A7R III now 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, while both S-Log2 and S-Log3 are also available. 

If you want to shoot Full HD footage you can capture this at up to 120fps, while there are ports for both microphone and audio monitoring.

Build and handling

  • Magnesium alloy construction
  • Dust- and moisture-sealed
  • Weighs 657g

The look and feel of the Sony Alpha A7R III broadly follow the design of the A7R II, but there have been a couple of subtle changes. 

While it doesn't get the dedicated drive mode dial/focus mode selector that sits to the left of the EVF on the Alpha A9, it does get a similar multi-selector joystick for quicker AF point selection. There's also the addition of a dedicated AF-ON button for back-button focusing, again as on the Alpha A9. In fact, the rear of the camera mimics the control layout of the A9 – that means the A7R III gets an additional 'C3' custom button, while the rear scrollwheel is more pronounced, and less likely to be accidentally knocked.

They all combine to make the A7R III that much more useable and satisfying to shooting with

The body is s thicker than the A7R II, and fractionally slimmer than the A9, and features magnesium alloy top, front and rear covers as well as an internal frame. Sony has also increased the number of lens mount screws to six for enhanced durability, while all major buttons and dials are sealed, and there's sealing throughout the body to protect the A7R III from dust and moisture.

The changes may be modest, but they combine to make the A7R III that much more user-friendly and satisfying to shoot with. 

Autofocus

  • 399 phase-detection points
  • 425 contrast-detection points
  • Eye AF with enhanced tracking performace

Sony has breathed over the A7R III focusing system as well. The 399 focal-plane phase-detection AF points remain (with 68% coverage of the frame), but Sony has bolstered the amount of contrast-detection AF points from 25 to 400. 

Sony reckons this overhaul should improve autofocus speed, delivering up to roughly two times faster AF speeds in low-light conditions, along with improved AF tracking performance. 

The Alpha A7R III can also focus in brightness levels as low as -3EV. When you consider that that's pretty much complete darkness, it's very impressive, although the D850's central AF point just edges it at -4EV.

The Alpha A7R III's Eye AF has also been enhanced, and now uses the same autofocus algorithms as the Alpha 9. This means that when the A7R III is in AF-C mode and with Eye-AF activated, the system should be able to continuously track and focus on your subject's eye, even if they look down or away from the camera.

When had a chance to test this out during our hands-on time with the camera, and we were really impressed. The A7R III managed to happily maintain focus on a subject in two challenging scenarios – while they were moving round the frame quickly, or looking down or away from the camera.

Performance

  • 10fps burst shooting
  • 5-axis image stabilization
  • 530-shot battery life

While the A7R II could only manage 5fps burst shooting, the enhanced processing power inside the Alpha A7R III sees the burst shooting rate double to 10fps, and that's with continuous AF/AE tracking. It can sustain this for up to 76 JPEG/raw images or 28 uncompressed 14-bit raw images. 

You have the option of using the A7R III's mechanical shutter to achieve this, or if you prefer, you can opt for the camera's electronic shutter for silent shooting. And, rather than having to impatiently wait while the camera writes large quantities of images to the card, it's still possible to use many of the A7R III's key functions.

The Alpha A7R III is kitted out with Sony's 5-axis optical image stabilization system, and this has been tweaked for the new camera to deliver a 5.5-stop shutter speed advantage, improving on the A7R II's 4.5-stop system. To reduce the risk of vibration and image blur, especially when shooting at 10fps, there's a new low-vibration shutter mechanism. 

One of the biggest complaints levelled at the A7R II was the poor battery life, with 270 shots possible if you were lucky. Sony has swapped out the W-series battery used in the A7R II and replaced it with its latest Z-series unit, and you can expect the A7R III to carry on shooting for 530 shots if you use the viewfinder, or 650 shots using the rear display. It's a welcome improvement, but still some way behind the likes of the Nikon D850's 1,840-shot rating. 

Image quality

  • ISO100-32,000, expandable to 50-102,400
  • 15-stop dynamic range
  • 14-bit raw shooting

We'll look at image quality in more depth when we get our hands on a final production sample and can take a close look at the raw files. For now, below are a selection JPEG files from our hands-on time with the Alpha A7R III.

Early verdict

If Nikon thought it was going to have it all its own way with the D850, it should think again. Sony has taken one of our favorite mirrorless cameras and bolstered the performance to make the new Alpha A7R III a much more capable and well-rounded offering.

The heady mix of high resolution and high performance is bound to help this camera appeal to an even broader range of photographers. We can't wait to get our hands on the A7R III for our full review.

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