What's new and how does it compare

The a7 III comes with a whole host of improvements compared to its predecessor, and stacks up well in the marketplace overall.

Key takeaways:

  • The a7 III's new sensor has the same resolution as the a7 II but comes with a new design for better performance in bright light and low light
  • The new 693 point autofocus system is a huge bump from the a7 II's 117 point system
  • Ergonomic enhancements make the a7 III much more responsive and pleasant to use than the a7 II
  • Compared to its rivals in the marketplace, the a7 III is well-positioned in a number of areas, particularly video, though its lower resolution viewfinder remains a concern

The single biggest update to the a7 III is its 24MP sensor. While it's the same resolution as the one used in the a7 and a7 II, it's now BSI (backside-illuminated) and has what's called a 'dual gain' design.

The Sony a7 III comes with an all-new sensor that's responsible for most of the updates relative to its predecessor.

The BSI design means that some of the wiring and circuitry is moved to the rear of the sensor, allowing for better low-light performance to some degree. Dual gain essentially means that the sensor has two 'base' ISO values that allow for either maximum dynamic range in bright light or better noise performance in low light, depending on your situation.

This sensor also brings with it a new autofocus system, with 693 on-sensor phase detection points that cover 93% of the frame. The updated sensor works in tandem with a new 'front-end LSI' (essentially an additional processor) to capture up to 10 frames per second with full autofocus and autoexposure, as well as allowing for oversampled (read: very detailed) 4K/24p capture from the full width of the sensor and 4k/30p from a slightly cropped region.

Beyond these internal changes are most of the external changes that came to the a7R III. The new Z-type battery banishes the 'battery anxiety' we felt with previous models, dual SD card slots allow for instant backup or overflow, and updated controls and menus allow for robust customization options, including separate button functions for video and stills.

Compared to full frame rivals

Though we regard the Sony a7 III's $1999 USD ($2600 CAD, €2300) MSRP to be reasonable for a full-frame camera body, there's no denying the price hike compared to its predecessor. But when you look at the details of what you're getting, it looks to us to be worth the premium.

Here's a high-level spec rundown against the Nikon D750 and Canon EOS 6D Mark II, with the older a7 II and higher-end a7R III thrown in for good measure.

Sony a7 III Sony a7 II Sony a7R III Nikon D750 Canon EOS 6D Mark II
MSRP (body only) $2000 $1700 $3200 $2300 $2000
Pixel Count 24MP 24MP 42.4MP 24MP 26MP
CMOS type BSI FSI BSI FSI FSI
Stabilization In-body
5 stops
In-body
4.5 stops
In-body
5.5 stops
Lens only Lens only
Cont. shooting rate (fps) 10 5 10 6.5 6.5

Rear LCD res dots

0.92M dots
/ 640 x 480
1.23M dots
/ 640 x 480
1.44M dots
/ 800 x 600
1.23M dots
/ 640 x 480
1.04M dots
/ 720 x 480

Touchscreen

Yes No Yes No Yes
Rear LCD articulation Tilt up/down Tilt up/down Tilt up/down Tilt up/down Fully articulating
Viewfinder magn. 0.78x 0.71x 0.78x 0.70x 0.71x
Viewfinder res (dots) 2.36M 2.36M 3.69M N/A N/A
Highest video res UHD 4K/30p 1080/60p UHD 4K/30p 1080/60p 1080/60p
Max bitrate 100 Mbps 50 Mbps 100 Mbps ~24 Mbps 60 Mbps
Log video? S-Log2, S-Log3, HLG S-Log2 S-Log2, S-Log3, HLG No No
Mic / Headphn Yes / Yes Yes / Yes Yes / Yes Yes / Yes Yes / No
Battery life (CIPA) 710/610 350 650/530 1230 1200
Weight (inc battery + card) 650g 600g 657g 740g 765g