Sony A7III v Canon EOS R


Although Canon would argue it has been part of the mirrorless party for some time, for many the company really only showed its true intentions late last year with the launch of the full-frame EOS R. Before then, the M series models, while popular for entry level users, never really offered a truly viable option for the more advanced user. But how seriously should you consider this full-frame model? Does it really have what it takes to challenge the established brands? We pitched it against one of the mainstays of the full-frame mirrorless market – the Sony A7III – to find out.

There’s little difference between the two models in terms of size and weight

Design and build

Right from the outset, there’s a key difference between these two models – and it’s the Canon that gets in a key early punch. Both models offer a full-frame CMOS sensor, but the EOS R’s offers 30.3 megapixels to the Sony’s 24.2. Processor-wise, the Canon uses the DIGIC 8 engine that was first seen in the EOS M50, while the Sony runs off the BIONZ X processor. This is the same processor as the original A7, but Sony say it’s been upgraded to offer an improved performance.

There’s less to divide the two cameras when it comes to physical dimensions. The Canon is the larger and heavier of the two, being a centimetre taller and wider than the Sony. This increased bulk doesn’t translate to a big weight difference, just 10g separates the two bodies with a battery and card on board.

Battery life remains an issue for mirrorless models, but it would appear that Sony has worked harder to keep its users shooting. According to CIPA standards, the Canon musters around 370 shots per charge, while the Sony delivers up to 710, which is a key benefit. Both models also offer the option of a battery grip to extend shooting time and improve handling. In both cases the grips accept two additional batteries.

Without the battery grips, handling is still good with well-sized handgrips and clear layouts available on both models. While the Sony opts for an analogue top-plate layout with mode and exposure compensation dials dominating, the Canon uses a top-plate LCD to present a greater level of information and user options.

The A7III has the advantage when it comes to lens options

Image quality

Resolution isn’t the be all and end all when it comes to image quality, but no-one can deny that the Canon’s 30.3 megapixels gives it a file size advantage over the Sony. Use every one of the effective pixels on the Sony’s full-frame sensor and you’ll be presented with a file measuring 6000 x 4000 pixels, while the Canon weighs in with a 6720 x 4480 file. In theory, then, you’ll be able to output even bigger prints with the EOS R. The Sony’s sensor, on the other hand, is back-illuminated which should boost image quality and enhance low light performance.

The Sony’s low light credentials are further enhanced by a marginally wider native ISO range which stretches to 51,400 as opposed to the Canon’s 40,000, plus the A7III can expand to 204,800, while the Canon’s highest expansion is 102,400. A 5-axis image stabilisation (IS) system is also on board the Sony body, which means you have shake reduction no matter what lens you attach to the camera. The Canon, in comparison, only offers IS in selected lenses.

When it comes to lenses, the Sony is at a clear advantage if you don’t want to start buying adapters. The A7III uses the E-mount for which there are currently over 40 lenses to choose from by Sony itself, plus further options from independent manufacturers including Tamron and Sigma. The Canon’s RF mount is very much in its infancy with just four dedicated optics. EF and EF-S lenses can be used with the optional adapter, but equally an adapter can be used with Sony for A-mount lenses on the A7III.

In terms of autofocusing, the Canon does have the edge, though, with AF sensitivity down to an amazing EV-6 (EV-3 on the Sony) and no fewer than 5655 user selectable focusing points (693 on the Sony).


The Sony and Canon will enable you to capture high quality video, making them both impressive all-rounders for stills and video. 4K at 30p is available on both models, but the Sony edges the Full HD frame rate, topping out at 120p while the Canon manages 60p at the same resolution. 120p is available on the Canon, but only at standard HD. 8-bit recording is standard across the pair, but the Canon offers 10-bit capture if you record externally via HDMI cable.

In terms of pure video making practicalities, both are perfectly well equipped with common features including headphone jacks and Log capture for colour grading in post-production, but the Sony certainly offers a greater level of fine-tuning and flexibility.

The Sony goes for an analogue top-plate layout, while the Canon squeezes in an LCD

Other features

Being highly-specified mirrorless models, there’s little doubt that both models offer plenty for the keen enthusiast or professional user.

If you like to shoot fast-moving action, the A7III has the advantage, offering a maximum shooting rate of 10fps for up to 177 JPEGs or 89 RAW files. Crucially, these figures include AF and AE tracking between frames. The EOS manages 5fps with AF/AE tracking or 8fps without, but for a maximum of 100 JPEGs or 47 RAW files. The Sony also has the advantage in terms of metering options, connectivity – it has Wi-Fi, Bluetooth and NFC, while the Canon has Wi-Fi and Bluetooth – and card slots. The A7III has dual slots, while the EOS has just one.

Conversely, the Canon offers a more detailed viewfinder featuring 3.69 million dots as opposed to the Sony’s 2.36 million and a more versatile rear LCD. Both models are touchscreen, but while the Sony’s tilts, the Canon’s is vari-angle and has 2.1 million dots (more than any other Canon) as opposed to the 921,600 on the A7III.

If it’s a versatile rear LCD you’re after, the Canon is the better choice


Being honest, it’s hard to look past the Sony in this head to head battle. It’s great for both stills and video, features in-body image stabilisation, is more powerful when it comes to continuous shooting and has superior battery performance. And all that before you consider the larger range of lenses on offer.

Make no mistake, the EOS R is a still highly capable camera and is sure to prove a hit with existing Canon users already heavily invested in the EOS system, or those moving into mirrorless and keen to maximise resolution or have bragging rights over the number of AF points. But based on the evidence of these two models, Canon still has a little way to go in the mirrorless market before it can seriously challenge the more established brands.

 Sony A7IIICanon EOS R
Resolution24.2 megapixels30.3 megapixels
ISO range100-51,200 (expandable to 50-204,800)100-40,000 (expandable to 50-102,400)
Video4K 30P/Full HD 120P4K 30P/Full HD 60P
Rear LCD3-inch, tilting, touchscreen, 921,600 dots3.15-inch, vari-angle, touchscreen, 2.1 million dots
ConnectivityW-Fi, Bluetooth, NFCWi-Fi, Bluetooth
Weight (body with battery and card)650g660g
Dimensions (WxHxD)126.9×95.6×73.7mm135.8×98.3×84.4mm