After years of slow evolution, Canon’s full frame mirrorless system has come to fruition with the release of two very interesting cameras. One of them, the EOS R6, challenges the likes of the Sony A7 III, Nikon Z6 and Panasonic S1 in the prosumer segment.
It’s difficult not to talk about the A7 III when it comes to full frame mirrorless cameras given its popularity. Despite the age and price difference, the EOS R6 is a direct competitor for the A7 III and its future successor. So let’s see what these two cameras have to offer.
Canon EOS R5 and EOS R6 coverage:
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Both cameras use a full frame (35mm format) sensor. The EOS R6 has 20.1MP, whereas the A7 III has 24.2MP.
Both cameras have a low pass filter to reduce aliasing and moiré, but the sensor structure is different: the Sony chip is a BSI type (back-illuminated) which collects light more efficiently than the traditional structure. This should, on paper, give an advantage to the A7 III in terms of dynamic range and high sensitivities. But since the Canon sensor is more recent, we should reserve judgement until we can perform a proper side-by-side comparison.
The R6 has a normal sensitivity range of 100 to 102400 ISO. There is a Low mode (ISO 50 equivalent) and one High value of 204800 ISO.
The A7 III ISO range goes from 100 to 51200 ISO. A low ISO 50 value is available too, and the maximum level with the extended setting is 204800 ISO.
The two cameras feature an advanced autofocus system with phase detection, which means that each focus point is driven by two small sensors that read the incoming light. The phase difference between the two sensors tells the camera how much correction is needed to have the subject in focus.
The way the two companies have developed this technology is different however.
On the Canon sensor, each pixel is composed of two photodiodes. The camera uses them together to create the image, and separately to evaluate the phase difference and acquire focus. Canon calls this Dual Pixel CMOS AF II, where II stands for the new version introduced with the R6 (and R5).
On the Sony sensor, the pixels are made up of a single photodiode, but a certain number of them embed the phase difference sensor that the camera uses to analyse and acquire focus. Phase detection points are used solely for autofocus, not to create the photo.
The Canon solution gives the R6 a distinct advantage: AF tracking can work across the entire sensor surface, and in fact Canon says that there is 100% coverage when face/eye detection or the Tracking AF mode are enabled. (It’s 90% horizontal and 100% vertical with the other AF area settings). When using the single AF point, you can move it across more than 6000 positions!
The A7 III phase detection coverage on the sensor is 93% which is not bad at all. There are 693 phase detection points and also 425 contrast detection points that can help in low light situations.
The minimum sensitivity for the EOS R6 autofocus is -6.5Ev with an f/1.2 lens or -5Ev at f/2. The A7 III works down to -3Ev with a f/2 lens. This means that Canon is 2 stops more sensitive in low light.
Both cameras feature face and eye detection. The Sony Eye AF mode is known to be the benchmark when it comes this kind of technology. Indeed the one the A7 III is very fast and reliable.
Canon has improved its face and eye detection with firmware updates on the original EOS R. For the R6, it introduces a new algorithm that should make the camera faster and more precise, as well as detect smaller faces in the frame when the subject is further away from the camera.
Furthermore, the R6 has a deep learning technology to detect the bodies, faces and eyes of animals such as dogs, cats and birds (even when they’re flying). The A7 III Eye AF mode can work for various animals too but it doesn’t detect the face or the body, and it doesn’t work with birds yet. (Read our report about Sony Eye AF for Animals.)
3. Continuous shooting speeds
The Canon EOS R6 can shoot up to 12fps, or 20fps if you use the electronic shutter. Continuous Autofocus and Exposure tracking remain active even at 20fps.
The Sony A7 III can’t match these specifications, with the highest frame rate being 10fps (with AF and AE tracking).
The buffer looks better on the Canon too: it can capture 240 RAW or 1000 JPG files at 12fps before slowing down. The A7 III does 89 RAW (compressed) or 172 JPG files at 10fps.
4. Image stabilisation
The EOS R6 is the first camera from Canon to receive 5-axis in-body stabilisation (along with the R5). Canon is the last company to incorporate this technology (Sony was the first to utilise it on a full frame camera with the A7 II in 2014) but the specifications are the best on the market.
The R6 offers up to 8 stops of compensation which is the highest rating of any camera (even better than high-end Olympus products). This rating can drop down to a minimum of 6.5Ev depending on the lens used, so not every lens will give you 8 stops of compensation. (See the full list in our R5 vs R6 article.)
The A7 III also has 5-axis stabilisation on the sensor but the rating is lower at 5 stops.
Both cameras can work with lenses that lack stabilisation (5 axes are used on the sensor) and lenses with optical stabilisation (3 axes on the sensor are combined with the lens IS).
Stabilisation works for video too, but the EOS R6 has an extra setting called Digital IS which adds electronic stabilisation to further improve the result. It crops the sensor as a result however.
In our experience, the A7 III IBIS is decent but to have a good keeper rate, you don’t want to go below 1/10s, unless you have the patience to check your image on screen and make multiple attempts. For video, it is fine if you don’t move but struggles more if you’re walking or even panning. Let’s say it has never been Sony’s forte up to now, despite being the first to use it on a full frame camera.
I have yet to try the EOS R6, but early reports from Canon ambassadors mention sharp shots taken hand-held at 2 seconds or even 4 seconds. If that were true, it would be pretty good but not unheard of in my experience since I was able to push the Panasonic S1R to the same slow shutter speeds. I’m curious to see what I’ll be able to do with the R6.
The EOS R6 marks a relevant step forward for Canon by including specifications for filmmakers that everybody has been waiting for.
The Canon camera can record 4K video up to 60p with full pixel readout (oversampling) with just a minor sensor crop of 1.07x. The maximum bitrate is 340Mbps (IPB). In Full HD, you can record up to 120fps with the High Speed mode.
The A7 III also records in 4K but the maximum frame rate is 30p with a 1.2x crop (24p and 25p use the full width of the sensor however). The maximum bitrate is 100Mbps. It too can record 120fps in Full HD, and you can choose whether to use the Q&S mode (slow motion effect directly in camera like the R6) or record in normal mode with sound (the slow motion effect needs to be done in post).
One clear advantage of the EOS R6 is that it can record 10-bit 4:2:2 internally (H.265 codec) with either the Canon Log gamma or the HDR PQ curve. The A7 III has two log profiles, HLG and several other settings designed to customise the image, but it is limited to 8-bit internally and externally (HDMI out).
Both cameras can record a maximum of 30 minutes per clip. The High Speed mode on the EOS R6 (1080p/120p) is limited to 7 minutes.
Another difference is the ISO sensitivity: the EOS R6 has a smaller range than for stills (100 to 25600) with extended values up to 204800 ISO. The A7 III has the same exact range for photography and video: 100 to 51200 ISO and extended values up to 102400.
Both cameras have a microphone input and headphone output.
6. Design and interface
The EOS R6 is the larger camera of the two, and it is a bit heavier too.
- EOS R6: 138 x 97.5 x 88.4mm, 680g
- A7 III: 126.9 x 95.6 x 73.7mm, 650g
The Canon has a larger front grip. Its design is very similar to the EOS R that we tested and preferred in terms of ergonomics over the A7 III (read our full comparison), and one of the key factors is the more comfortable grip. On the Sony, you need to cramp your fingers together which can be tiring when using heavy lenses all day (you can of course buy a grip extender to improve this).
Both cameras are built around a magnesium alloy chassis and offer weather-sealing.
The two cameras offer a good number of controls with an AF joystick and various dials and buttons around the body, and most of them that can be customised. The A7 III has an exposure compensation dial on top that the R6 is missing. Unique to the RF system however is the function ring of the lenses that can be used for different settings.
Both cameras have two SD card slots with the difference being that both slots are UHS-II compliant on the R6, whereas on the Sony only slot 1 is.
Finally, you’ll find a USB C and Micro HDMI port on both, as well as wifi and bluetooth wireless connectivity.
7. Viewfinder and LCD screen
The EOS R6 has a viewfinder with more resolution (3.69M dots vs 2.36M dots) and a faster refresh rate (120Hz vs 60Hz). The magnification is slightly larger on the A7 III (0.78x vs 0.76x) and the eyepoint is the same (23mm).
Another difference concerns the rear screen: the R6 has a multi-angle solution where you can open it to the side and rotate it 180˚, whereas the one on the Sony tilts up and down.
The resolution is higher on the Canon (1.62M vs 0.9M dots) and the R6 offers a more complete touch screen experience including navigating the menu, whereas on the A7 III you can only move the focus point or double-tap to activate magnification.
The EOS R6 has a newly developed battery that increases the power by 14% while maintaining the same form factor as the previous one. The official rating is 380 frames (EVF) or 510 photos (LCD) per charge, although you will be able to take more in real life.
The A7 III has a rating of 610 (EVF) or 710 shots (LCD), and I can easily double that in real world conditions.
Both cameras can be charged via USB but you will need a high current charger for the Canon. A battery grip is available for both product.
One small annoying thing about the A7 III is that it comes without a battery charger (the camera must be plugged straight into the wall socket with the USB adapter). You can of course buy one separately.
The Canon RF system was launched two years ago, and Canon started from scratch without even including compatibility with its EOS M APS-C mirrorless system. (The mount is different, unlike for its EF DSLR system that shares the same mount for APS-C and full frame cameras.)
I have to admit that in this short amount of time, Canon has worked hard to release a lot of high quality lenses, from the 2.8 zoom trinity to fast 1.2 primes to super telephotos. There aren’t a lot of affordable lenses for now, but I’m sure more will come in the near future. The total number of lenses is 15 plus two teleconverters. Of course with the EF to RF adapter, you have access to all the EF DSLR lenses while maintaining excellent autofocus performance.
The Sony full frame E-mount system debuted in 2013, and in seven years the company has built an impressive number of native lenses. The same mount is used for its APS-C series as well which increases the versatility of the system. Third party brands such as Sigma, Tamron, Samyang and Zeiss are actively releasing new lenses for E-mount, so users are now spoiled for choice.
I’m pretty sure that we will start to see more third party RF lenses at some point, and once again you have access to the DSLR equivalents, although it is fair to say that EF lenses work well on the A7 III too and there are many adapters available.
One last curiosity: when the R6 is turned off, the shutter closes to protect the sensor while changing the lens, just like the EOS R.
The EOS R6 starts at a retail price of $2500 / £2800 / €2500 for the body only.
The A7 III has been around for two years now. And its retail price has dropped a bit in some countries ($2000 / £1750 / €1950). You can also come across some offers from time to time and might be able to get a better street price.
Note: prices are as of July 2020. US dollar prices are without tax.
For years we’ve been reprimanding Canon for not offering better specifications on its mirrorless product, while Sony kept pushing the mirrorless revolution. Now, it looks like Canon is finally ready to fight back.
The EOS R6 offers a nice blend of high quality specifications and promising performance: the most advanced AF system from Canon to date, impressive continuous shooting speeds, 4K 60p and 10-bit video, possibly the best image stabilisation on the market, all in a body whose design and ease of use has always been the brand’s forte.
With the A7 III, we must take into account that it is now two years old, so what now looks like an inferior product could push its way back to the front whenever the A7 IV makes its appearance. For now, you can count on a lower price, a vaster selection of native lenses if you’re not interested in adapting, and an excellent sensor that might still be at the top of its class.
Check price of the Canon EOS R6 on:
Canon EOS R5 and EOS R6 coverage: