Canon R5 vs Sony a7S III vs 1D X Mark III – the Ultimate Video Shootout

The past few months have been a near-constant stream of exciting camera news. It has completely changed the camera landscape and now we all had to check out all the new stuff and compare it with all the old to see who are the real winners. If we look deeper at mirrorless/DSLR picks for video the Canon EOS R5 and Sony a7S III are perhaps the best – or most talked about – right now.

Parker Walbeck and Landon Bytheway from Full Time Filmmaker have gotten their hands on the R5 and a7S III and added in their workhorse Canon EOS-1D X Mark III to put them into what they call, “The Ultimate Video Shootout.” Considering all the different situations and environments they tested them all in it is looking like it will deliver on that promise.

They point out that this is a fairly subjective comparison. This isn’t done in a vacuum. These are are fairly real-world environments. They also use a fairly simplified point system to judge the cameras. Also, these comparisons focus on the video performance, meaning stills features will not be weighted to highly here. This is broken down into a ton of sections, but if you just want to see the winner skip down to the end.


Budget plays such a big part in any decision, so it only makes sense to start there. As of the video’s release the Sony a7S III is $3,500, the Canon R5 is just a bit higher at $3,900, and the Canon 1D X Mark III is the priciest at $6,500.

This all makes sense. The a7S III and R5 are both similar in design and target market while the 1D is a flagship DSLR. It’s easy to see who are the winners and losers here.


This is an interesting one. Purely talking resolution the R5 takes the crown as it delivers up to 8K. Of course, there are limitations to the 8K mode and just practical reasons to not use it all the time. The 1D X comes in second as it has a 5.5K raw video option, and then finally there is the a7S III which stuck with exclusively 4K. Another quite simple comparison.

Best 4K Image

This is going to be where it gets a little subjective.  Shooting at each camera’s highest quality 4K mode and then doing a 400% crop in you can see some small differences between the three.

They determined that the a7S III is the softest and had some artifacts, likely due to the use of a low-resolution 12MP sensor. The 1D X came in second, though they point out it was nearly indistinguishable from the R5. But, the R5’s HQ mode having downsampling from 8K has advantages, minus the overheating.

Now, if you turn the R5’s HQ setting off, then the 1D actually squeaks ahead in quality. Though, the Sony still comes in last.

Slow Motion

All three cameras offer solid slow motion recording. The R5 and a7S III, however, both offer 4K 120p while the 1D is limited to 120p in Full HD. The R5 has some limitations, no sound and automatically slowed down to 30p as well as triggering the overheat warning, while the a7S III seems to treat it just like any other shooting mode besides a small 1.1x crop.


All these camera boasted revamped AF systems when they were released. The R5 and a7S III promised incredible improvements and that seems to be true here. The mirrorless models both performed equally well. On the other side, the 1D was noticeably slower to respond.

Color Science

I’m not sure if there is a more subjective topic for cameras today. I will say that people tend to prefer Canon colors and have seen some issues with Sony’s science.

As for skin tones, both Canons seems to excel in providing a natural look while Sony had some green and yellow that isn’t too flattering. A slight green tint was noticed on other Sony footage, though admittedly it is easy to correct in post.

Bit Depth

I actually have to do a minor correction to the video here. They call out the 1D X as the best since it has 12-bit raw and then call the R5 only 10-bit raw. Per Canon’s spec sheet, the Canon RAW video format is in fact 12-bit on the R5, making it equal to the 1D.

Internally, Sony only goes up to 10-bit, putting it behind these raw formats. Though, it has an upcoming 16-bit raw output that can be recorded as 12-bit ProRes RAW using the Atomos Ninja V. Native recording will go to Canon’s internal raw, but the Sony could compete here with it’s output.

Dynamic Range

On paper, the a7S III leaps ahead here with 15 stops of dynamic range. The Canon Log format limits both the R5 and 1D X Mark III to 12 stops. Even in their very basic testing outside with a subject in shadow in the foreground you can see more detail was available in the a7S III’s image. Sony is clearly in first and the R5 looks to handle highlights a little better than the 1D.

Compressions/File Sizes

It’s a little unclear what formats they were using, but in their usage, the a7S III files came in at a quarter the size of the Canon files. Another benefit was that the Sony footage played back very smoothly during editing. Both Canon cameras had some stutters in playback.

Low-Light Performance

This should be the least surprising of the tests. The Sony a7S III is the king of low light thanks to its 12MP sensor. As this is a fairly expected aspect of modern digital sensors, the 20MP 1D came in second and then last was the R5 with its high 45MP resolution. All performed well, but if you want the best low-light shooting you’ll want the Sony.

Body Size

Another obvious one, the two mirrorless options are much smaller and lighter than the full-size 1D and its DSLR design. The a7S III is technically a touch smaller and lighter so it wins here. This means the winning order is a7S III, R5, and then 1D X Mark III.

Battery Life

Where the 1D’s large body comes in handy is fitting a large battery. This puts it ahead for battery life where it can record 3 hours of 4K video on a single charge. The a7S III is about 3 hours, so a little behind there. And, finally, the R5 only has 2 hours of battery life.

Ease of Use

Sony may have given the a7S III a brand-new menu that is much easier to understand and has touch support, but Canon is still much better out of the box. Canon is also more touch capable with the ability to adjust nearly anything you want by tapping the screen.

Between the R5 and 1D X, the slight updates to certain menu options (like frame rates and resolutions), give it the edge. A bonus to the R5 is the use of a vari-angle screen and the addition of control rings to RF lenses.

Flip Screen

Another straightforward comparison: the a7S III and R5 have fully articulating screens while the 1D has a fixed screen. Win goes to mirrorless.

Screen Resolution

Now if we want to differentiate based on the quality of the aforementioned screens, the Canon’s both has larger 3.2” 2.1m-dot screens while Sony has a 3.0” 1.44m-dot screen that is a good deal worse in bright sunlight.

Dual Recording/Recording Limits

All the cameras have dual card slots, but only the a7S III can dual record. Both slots on the a7S III are matched and support either CFexpress Type A or SD.

It also doesn’t have a recording limit, can create proxies, and can automatically switch cards without needing to pause recording. Both the Canon’s have dual card slots but don’t have the other benefits except for proxies when shooting raw video.

Image Stabilization

Canon made some headlines thanks to its 8-stop image stabilization on the R5, and it clearly shows its advantages in this test. It looks so smooth. The a7S III is okay but can be very jerky still. The 1D X doesn’t have any built-in stabilization so relies solely on digital stabilization which is far from ideal.

Focus Peaking/Zebras

You can’t underrate built-in focus and exposure tools. The R5 and a7S III have both focus peaking and zebras, though Canon’s is preferred. The 1D surprisingly has peaking but no zebras, putting it in last.

Rolling Shutter

Ah, the bane of nearly all CMOS-based video cameras today: rolling shutter. This was a huge problem in the early days of DSLR and mirrorless video, though we have seen it become less and less talked about over the years.

Sony promoted improved performance here with the a7S III and was definitely telling the truth, beating out both Canon’s with ease. The R5 happened to place in second, and the 1D X Mark III was noticeably worse.


Sony has developed an ecosystem of accessories for shooting video, putting them ahead here. The notable call out is the Multi Interface Shoe and its ability to accept digital audio. This enables cable-free mic setups. The batteries and cards are quite equal in function and pricing. The 1D, however, does have much pricier batteries.

Lens Options

Canon has been around a lot longer and has a lot more experience to show in their lens options. Also, their RF line has been stellar so far, perhaps beating out many of the Sony options.

That means the R5 takes first since it’ll worth with RF or EF glass, the 1D X is second with an extensive EF lineup, and then Sony is in last. I will point out that Sony has much more third-party support than RF at the moment, but the fancy RF adapters from Canon are awesome.

Overall Reliability

All three cameras offer good weather sealing and durability. There is no reason to believe they wouldn’t all hold up. The 1D X Mark III does seem to offer a step up in build quality and durability. It is a known and proven reputation of the 1D series. The 1D also never overheats. Factoring in overheating, the a7S III comes in second, since the R5 has known overheating limitations. The limits seem to be coded into the firmware, making it incredibly hard to recommend for pro applications.

Best Photo Camera

We did say the video specs were going to be more heavily weighted, but we can’t forget about the photo side. Having a dual-purpose camera is a key advantage to DSLR and mirrorless cameras. The Canon R5 shows that it was probably bad marketing that sidelined it as opposed to poor performance. The R5 is an amazing stills camera with a great 45MP sensor. The 1D comes in second with its 20MP sensor and finally there is the a7S III with just 12MP.

Final Thoughts

At the end, the tally came to 24 points for the Canon R5, 14 points for the Canon 1D X Mark III, and 24 points for the Sony a7S III. Though, Parker put an asterisk on the R5 for its overheating concerns. Interestingly, the 1D X is still Parker’s pick for a workhorse camera still.

The a7S III seems to offer the best value here, coming very close to the 1D but at nearly half the price. It does get dinged for less intuitive controls, less desirable color science, and a poor LCD. Also, they are sunk deep into Canon lenses, making a switch difficult since you seem to lose AF at the moment.

That was a rapid fire comparison and ended up being quite lengthy. Still, it is a good comparison if you are looking for a new camera. 

[source: Parker Walbeck]

Order Links:

  • Canon EOS R5 Mirrorless Camera (B&H, Amazon)
  • Sony Alpha a7S III Mirrorless Camera (B&H, Amazon)
  • Canon EOS-1D X Mark III DSLR Camera (B&H)
  • Atomos Ninja V 5” 4K HDMI Monitor/Recorder (B&H, Amazon)

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