The Sony a7S III Vs. The Canon EOS R5: Two Mirrorless Approaches

Sony A7 SIII Vs. The Canon EOS R5

Canon has introduced the EOS R5, a full-frame mirrorless camera with almost unbelievable specs that have turned out to be true—with some caveats.

Canon Heats Things Up With The R5 Rumors

Things have really heated up in the mirrorless camera category. July 2020 saw the introduction of two eagerly awaited entries into the mirrorless camera wars, one from Canon and one from Sony. Rumors about Canon introducing a potential RAW capable 8K mirrorless camera, as fantastical as that seemed, surfaced last year. Would it be possible to build a small, mirrorless camera with IBIS, RAW recording and 8K without it becoming a heat-generating monster that shuts down constantly? More on this later.

Sony A7 SIII Vs. The Canon EOS R5
The Sony A7 is the camera that started the video-capable mirrorless camera phenomena in 2013. The latest A7 variants don’t look terribly different.

Five Years of Sony Rumors

On the Sony front, there have been rumors of a new a7S III full-frame mirrorless camera for literally years. Sony presents a very different marketing scenario than Canon in that the Sony a7 lineup began the mirrorless camera revolution when the first two Sony a7s (the a7 and a7R) were introduced way back on October 16, 2013. Less than a year later, Sony followed with the a7S for a total of three variants on the market by April of 2014. The cameras were simple to use and presented an image that was easy to cut with footage with Sony’s popular F55, F5 and A7 cameras, so they gained great popularity as a B-camera for these A-cameras.

Most of the a7 camera variants have been advertised and used as a true mirrorless hybrid, often pulling double duty as a stills camera and a video camera. Sony introduced a more video-centric model, the a7 SII, in October of 2015. Its 12.2mp sensor, while low for a stills camera, features a much larger pixel pitch and, therefore, is considered to have larger pixels that are able to gather light more efficiently for low light video shooting especially. The a7S II, being five years old, has seemed a bit long in the tooth though. The recording specs of 8-bit, 4:2:0 at a measly 100 mbps, in 2020, seem to be a throwback to 2015 when almost all cameras were 8-bit and higher data rates were relegated to only high-end cameras for the most part.

Sony A7 SIII Vs. The Canon EOS R5
Canon introduced the EOS R, its first full-frame mirrorless camera in 2018.

The Canon EOS R And RS

Canon introduced the EOS R in October 2018. It was the first higher-end Canon mirrorless camera aimed at video shooters, serving as a B-camera for Canon shooters who were already utilizing cameras like Canon’s EOS C200 and C300 MKII. The EOS R had some impressive specs and utilized Canon’s new RF lens mount and a 30.3 megapixel full-frame CMOS sensor and the DIGIC 8 Image Processor. Canon put a lot of new and interesting technology into the EOS R, but when I evaluated it as a B-camera for my own C200 and C300 MKII, I found that its 1.7x crop when shooting in 4K paired with some truly unflattering rolling shutter artifacts doomed it for me. Great stills camera, but as a video camera, those two factors alone threw the camera into non-contention for many video pros. Canon followed up a few months later with the EOS RP, which seemed to basically be a bargain version of the EOS R, with fewer features and usability for about half of the EOS R’s introductory price of $2,299. I’m not privy to Canon’s actual sales figures, but anecdotally, none of the Canon shooters I know who own the C200 and or C300 MKII bought the EOS R or RP as B or gimbal cameras. The cameras probably did much better sales to still shooters.

Sony A7 SIII Vs. The Canon EOS R5
Canon has continued to develop its high-end pro-level DSLRs with the EOS 1DX MKIII, but the mirrorless EOS R5 may have ensured that this is the last high-end DSLR Canon creates.

Canon Puts Their Plan Into Action

The reception for the EOS R and RP, to me, seemed tepid. Most Canon owners surmised that Canon must have had something up their sleeve to introduce a more professional, higher-end model to the EOS R family. Canon’s bread and butter DSLRs like the EOS 5D MKIV and the EOS 1DX MKIII are great cameras, but they’re larger, heavier DSLRs, not smaller, lighter mirrorless cameras. The market has clearly been leaning toward smaller, mirrorless cameras, so Canon had to go all-in on a new EOS R variant. Most importantly, Canon has its new RF line of glass that has been on the market since the introduction of the EOS R back in 2018. But with only two non-pro bodies available, it’s hard to imagine that the sales of the more expensive new RF mount lenses haven’t surpassed Canon’s expectations. Canon has sold literally billions of EF and EF S lenses worldwide, and lens sales continue to be a huge revenue source for Canon, so they have a strategic interest in boosting the sales of the RF mount lenses.

Sony A7 SIII Vs. The Canon EOS R5
The Canon EOS R5 was introduced with a spec sheet that almost defies belief, the ability to record 8K RAW internally. But at what cost as far as usability?

Retailing for $3,899, the Canon EOS R5 was introduced on July 9, 2020. The headline features are numerous and impressive:

  • 8K Canon RAW Video up to 30p.
  • 8K DCI and 8K video up to 30p @ 4:2:2 10 bit Canon Log H.265 or 4:2:2 10 bit HDR PQ H.265.
  • 45MP Canon CMOS sensor.
  • High-speed sensor readout.
  • New DIGIC X image processor.
  • Full width of the sensor is used when recording 8K.
  • 4K DCI/UHD at up to 120p 4:2:2 10 bit Canon Log.
  • All recording modes and frame rates can be recorded internally.
  • First Canon camera with IBIS.
  • Dual card slots: Express and UHS-II SD.
  • DPAF II available in all modes and all frame rates including high speed.
  • Animal, eye and face detection.
  • Vari-angle LCD touchscreen.
Sony A7 SIII Vs. The Canon EOS R5
Early reports and testing reveal that there’s a price to be paid in order to gain the specs that make the EOS R5 such an eye-grabbing proposition.

Canon EOS R5 Analysis And Observation

Canon has yet to ship the EOS R5, and I’ve been in line to receive a review copy, so I have no hands-on experience with the EOS R5 yet, although I intend to get some hands-on time with one as soon as possible. Aside from hands-on though, many YouTubers and reviewers have been able to play with EOS R5 prototypes. We have some good field observations about the camera (and its lower cost, lower specification brother, the EOS R6) and many have already tested heat generation and the camera’s ability to operate without overheating and shutting down. As a technology showcase, looking at the specs, Canon shot for the moon. They seemed to want to exceed everyone’s idea about what’s possible in a relatively tiny mirrorless camera body. Three years ago, if you had told me that you could pack 8K RAW with a 45 MP sensor into a body that weighs 1.62 pounds, I wouldn’t have believed it possible, but Canon has done it.

Specs At What Cost?

I don’t have room to list every spec from the EOS R5, all of the posts and discussions that have taken place on every video and digital cinema forum and discussion group. A short synopsis of the situation might read something like, “Canon users request every potential resolution and codec option possible. Canon, listens, goes into the woodshed, develops, tests, tests and then releases EOS R5 and exceeds almost every requested specification nicely. Final camera specs and prototypes are released. Early users of prototypes report that the camera isn’t able to shoot at its highest resolutions and frame rates without overheating and shutting down. Other users report that under certain temperature and operational scenarios, camera can’t even record at its smaller and less demanding resolutions for as long as specified, quality and frame rates without shutting down after just a few minutes. Chaos ensues; discussion boards go nuts with arguments and defense as well as attacks of camera. Canon releases their own rebuttal about the overheating.”

I have read plenty of sentiments about “The Canon R5 is a hybrid stills camera that is capable of shooting 8K RAW FF video with IBIS. You shouldn’t consider it a professional video camera, it’s not, it’s a stills camera that shoots video.” I’ve also read posts that take the opposite tact, “Canon has promoted the heck out of the EOS R5 as a pro-level video tool. How many hobbyists and still photographers want to shoot 8K RAW?. This is a pro video tool and Canon has failed because the camera experiences thermal shutdown too often and sooner than the specs suggest.”

Canon issued the following chart listing approximate shooting times at various raster sizes, frame rates, and quality levels.

Sony A7 SIII Vs. The Canon EOS R5
Canon has put this list into the press, listing some approximate times the EOS R5 can shoot video before experiencing thermal shutdown. There’s no free ride when generating such tremendous amounts of heat in such a small, confined camera body with no fan for cooling.
Sony A7 SIII Vs. The Canon EOS R5
The Sony A7 SIII has been expected for years and now that it’s finally here, the specs look solid, but the ability to shoot without thermal overload must surely be one of its headline features.

Sony Counters With Iterative Improvement

Sony recently introduced the brand-new a7S III. To say this camera has been widely anticipated would be a gross understatement. Frankly, Sony has let their a7 variant mirrorless camera lineup stagnate, most of the recording specs in any of the models other than this latest model are circa 2015 specs and it’s five years later. Panasonic, Canon, Fujifilm and Blackmagic Design, although their cameras are cine cameras and not mirrorless hybrids, have not stood by idly. Panasonic offers the full-frame S1 and S1H mirrorless hybrids, which have an amazing array of cinema camera technology in a mirrorless form factor. Canon now has a lineup of four EOS R variants including the new R5 and R6. Fujifilm has stuck with APS-C sensors with their excellent X-T3 and X-T4 and are cultivating a line of medium-format GFX cameras that are also video-capable. Blackmagic Design has had amazing success with its Pocket Cinema 4K and 6K cameras—both very capable, inexpensive and flexible.

Sony has a lot of ground to make up in bringing back video-centric mirrorless camera users into the fold, and the a7S III presents a compelling package, albeit they took a very different path than Canon did with the R5 and R6. Here are the headline features for the a7S III:

  • 4K at 120fps 4:2:2 10-bit (1.1x crop) time recording limit of 30 minutes.
  • 4K RAW up to 120p over HDMI.
  • HD 240 fps (no crop).
  • Internal 4K up to 60p 4:2:2 10-bit internal.
  • No time restrictions on 4K 4:2:2 10-bit up to 30p.
  • 1 hour time restriction on 4K 60p 4:2:2 10-bit internal.
  • Improved autofocus performance.
  • Articulating rear LCD screen.
  • Redesigned menu system.
  • New Electronic IS.
  • Down sampled 1080P.
  • Full-sized HDMI.
  • Decent codec.
  • S-Log 3 and Cinetone.
  • Decent amount of DR.
Sony A7 SIII Vs. The Canon EOS R5
The A7 SIII features a full-size HDMI Type A connector. Believe it or not, this is a huge deal as the type A connector is leagues more reliable and robust than the Micro HDMI connector many mirrorless cameras get by with.

As you can see, Sony has improved just about every core feature of the a7S III. But the keyword here is “improved.” There are no headline-grabbing features like the 8K Internal RAW recording of the Canon EOS R5. There’s a full-sized HDMI connection, which is great. One of the headline features though is no overheating. No recording time restrictions on 4K 4:2:2 10 bit at up to 30p; this is the bread and butter raster and frame size that most of us shoot in in 2020. The camera features a conservative 12 MP sensor, while the Canon R5 has a 45 MP sensor. This means that the a7S III should be more sensitive when working in lower light. The Canon may be able to create much higher raster and resolution sized still images. Sony has made a point of telling us that you can buy the a7S III and count on it working; it has a new passive cooling system designed to keep things from overheating. However, even with this new passive cooling architecture (there’s no fan), I’ll still be very interested to see how this performs with the camera shooting 4K 60p in a hot outdoor shoot with the sun beating down on the camera body.

Sony A7 SIII Vs. The Canon EOS R5
Sony has packed the a7S III with lots of improvements on existing features and technology. Is this a better approach than Canon’s spec driven EOS R5?  Time and the market will tell—it will be interesting to see which camera sells more copies.

What Does This Mean?

While I haven’t had hands-on time with either camera yet, I still thought that a little analysis of what Canon and Sony have put out would be worthwhile to talk about. We have the two largest camera manufacturers in the world who have put out new, state-of-the-art mirrorless hybrids that have diametrically opposite design and feature goals. Both models seem to be amazing technically, and the images I’ve seen from each, both stills and video, seem to look impressive. Is one approach better than the other—state of the art, pushing the limit headline features versus conservative, iterative feature growth? The answer to that probably lies with the type of shooter you are, what you shoot, where you shoot it and who your clients are.

For me, I’d have a hard time working within the temperature limitations of the R5. I often shoot outdoors, in direct sunlight, often shoot long takes, several in a row when shooting documentaries. For this work, I couldn’t risk the temperature limitations of the EOS R5, and I’d probably take a harder look at the a7S III. For other types of work and workflows, the a7S III might not have the higher raster size of the R5, but it’s seemingly more robust (I reserve judgment until I can put both cameras through their paces) running times without dealing with thermal overload would be appealing. Both cameras seem to have excellent AF tech and both have IBIS. The Canon’s RAW recording could be appealing when shooting in lighting and with subject matter that would benefit from a RAW workflow. With the a7S III, RAW can only be recorded externally and the recorder that can deal with the 16-bit RAW doesn’t yet exist, but the Atomos Ninja V will record 12-bit ProRes RAW or ProRes via the a7S III’s HDMI connection.

Ultimately, it seems we’ve reached a point where mirrorless cameras seem to have become the technical hotbed of feature innovation, and it’s exciting to have two such impressive choices to choose from. Both are impressive tools for all kinds of production.