Video

The EOS 5DS and SR offer broadly the same video options as the EOS 5D Mark III. There's a choice of compression options, with ALL-I (where each frame is compressed individually) or IPB compression (where only the differences between key frames are retained) available at up to 1080/30p. 60p recording is only possible at 720 resolution, limiting the options for shooting footage for playing back as slow motion.

The 5DS/R cameras are missing key video-centric features, like focus peaking and zebra (highlight) warnings. And while it's safe to say that pro-videographers won't turn to the 5DS cameras for video shooting, these features are available on many of the 5DS' mirrorless counterparts.

Video Quality

Our video still isn't, of itself, a test of video quality (since that can't sensibly be assessed without seeing how the cameras reproduce motion), but gives an idea of how the camera's sensor is being sampled and the degree to which it's being sharpened.

Interestingly, the 5DS R (and, by inference, the 5DS) seems to achieve its video very differently than the 5D Mark III. Whereas the Mark III bins its pixels together, the 5DS R appears to be skipping readout lines to get down to the 1080 resolution (the giveaway being the asymmetrical rendering of moiré on the Siemens stars around the scene's central target). Despite this, its results to appear to be fractionally more detailed than its lower-res sibling.

Compared to its two most obvious peers, the results look very similar to those of the Nikon D810, both in terms of detail and capture artefacts, but with slightly more aggressive sharpening on the Nikon. The 5DS footage appears to handle aliasing and moiré better than the D810, though. The Sony Alpha 7R II looks better in both respects, when shot at 1080 using the near full width crop of its sensor. But, good though this probably pixel-binned footage is, it's capable of significantly better results by shooting 4K footage from the Super 35 region and downsizing (which you can read more about in the a7R II review).

Good Light vs. Nikon D810

In this test we see the Canon EOS 5DS R shot side-by-side with its nearest DSLR rival: the Nikon D810. While both cameras' makers promote their video capabilities, the reality isn't quite so video friendly. Both cameras lack focus peaking to aid manual focus. The Nikon offers limited choices of compression or bitrate while the Canon omits zebra warnings to assess exposure. 

In this video you can see that the Canon's footage appears fractionally less detailed than the Nikon's (with the difference looking like a slight difference in sharpening). This lower sharpening, if anything, provides more freedom at the editing stage. The only option for shooting at 60p on the Canon is to drop to 720p which, as you'd expect, looks significantly worse than the D810's 1080/60p footage.

Overall the footage is fine but not particularly impressive for a camera costing this much. This just reinforces our impression that the 5DS and SR are primarily intended for a stills-shooting audience.

Low Light Performance vs. Sony a7R II

Here we look at the low-light performance, in this case compared with the Sony a7R II.

The EOS 5DS R does pretty well in this test, producing usable footage despite being at ISO 12,800. There's little sign of temporal noise (dancing patterns in the shadows, of the kind you can see in the Sony's Super 35 1080 footage, for example), but there's also very little detail. The noise reduction that's keeping everything clean is also giving a rather over-smoothed, waxy effect to the subject's skin on the darker side of his face.

Overall, the results are competitive with most of the a7R II's output modes from a noise perspective, barring the a7R II's very best performing 4K Super 35 mode which excels in most, if not all respects. That said, the footage is never quite as detailed as any of the 4K modes on the a7R II.

Handling/Controls

The 5DS and SR includes a reasonable number of features for videographers but a number of others are absent. So, while it offers the same bitrate options as the EOS 5D Mark III, it doesn't have a headphone jack for audio monitoring. Like all Canon DSLRs, it's missing features such as focus peaking, zebra warnings and flat gamma profiles that increasingly appear on competing models (and on Canon's Cinema EOS cameras).

Autofocus

Below you can see how the video autofocus compares to that of the Sony a7R II and the Nikon D810, first with fairly simple back and forth motion, then with slower more erratic movement tracked using Face Detection:

The 5DS' contrast detect-only AF (CDAF) system means it cannot keep up with the Sony a7R II's depth-aware, on-sensor phase-detect AF system in video. The 5DS R spends much of its time catching up as our subject moves, meaning realistically most of the footage is out of focus. Compare this to the limited hunting the a7R II displays, keeping our moving subject largely in focus for most of the video.

That said, in comparison to the Nikon D810 Canon has done an impressive job of settling at a focus point without too much wobbling back and forth for confirmation, especially considering its CDAF-only system. The Nikon readjusts focus only intermittently and, when it does so, exhibits significant hunting, resulting in a jarring experience. The Canon's result wouldn't make the cut for dedicated and discerning videographers but they're not overly distracting for personal projects. Note that the lack of focus peaking means magnified live view is your best bet for accurate manual focus, short of focusing off a live HDMI feed on a higher resolution monitor.

Overall, that's the story of the EOS 5DS and SR: it's perfectly usable as a video camera, but it hasn't been designed with serious videography in mind.

Overall, that's the story of the EOS 5DS and SR: it's perfectly usable as a video camera, but it hasn't been designed with serious videography in mind. Both the video quality and the level of support tools provided is more appropriate for stills shooters wanting to dabble in video than it is for anyone with serious video aspirations. It's hard not to get the impression that Canon would much prefer those users buy a camera from its Cinema EOS range.