Canon EOS 5DS / 5DS R First Impressions Review

Canon has added to its EOS 5D range with the launch of two 50MP cameras, the 5DS and the 5DS R. Both cameras are high-resolution full frame models, primarily aimed at stills photographers. The only difference between the models is that the 'S' has an optical low-pass filter, while the 'S R' has a self-cancelling filter (the same relationship as Nikon's D800 and D800E models shared).
The two cameras will exist alongside the EOD 5D Mark III, acting as dedicated high-resolution cameras primarily intended for studio, landscape and wedding shoots, rather than the all-round capability offered by the existing model. The Mark III still trumps the S and S R in terms of maximum ISO and continuous shooting speed.
Slightly unusually for Canon, both models have been announced a long way ahead of their June 2015 availability date, so we wouldn't be surprised if some of these details changed between now and then.

Canon EOS 5DS / SR key features

• 50MP CMOS sensor
• 5fps continuous shooting
• ISO 100-6400 (Extends to 12,800)
• 61-point AF module with input from 150k pixel metering sensor
• Dual Digic 6 processors
• 3.0" 1.04m dot LCD
• CF & SD slots (UHS-I compatible)
• 1080/30p video
• M-Raw and S-Raw down-sampled formats
• 30MP APS-H crop and 19.6MP APS-C crop modes
• USB 3.0 interface

Most of the big new features on the high-res 5Ds are about ensuring you're able to get the best of the cameras' extra resolution. Our experiences with the Nikon D8X0 series cameras has shown us that simply having a high resolution sensor isn't enough: to take full advantage of it you need to really obsess about stability.
To this end, Canon has reinforced the tripod socket and surrounding area to allow stable engagement with a tripod. It has also used a more controllable, motorized mirror mechanism, like the one in the EOS 7D II, that allows a deceleration step before the mirror hits its upper position - reducing mirror slap.
The third change a revised mirror lock-up mode that allows you to specify an automatic delay between the mirror being raised and the shutter opening to start the exposure. It allows the user to choose the shortest possible delay that has allowed mirror vibration to subside: maximizing sharpness while minimizing the loss of responsiveness.
Although the S and the SR can both shoot movies with the same choice of frame rates and compression as the 5D III, they don't offer clean HDMI output or headphone sockets. The message is pretty clear - if video is a major concern, these aren't the cameras for you.

	Canon EOS 5DS	Canon EOS 5DS R	Canon EOS 5D Mark III
Pixel count	50.2MP	50.2MP	22.1MP
Processor	Digic 6	Digic 6	Digic 5+
Maximum ISO	ISO 6400 (12,800 ext)	ISO 6400 (12,800 ext)	ISO 25,600 (102,400 ext)
Maximum ISO	ISO 6400 (12,800 ext)	ISO 6400 (12,800 ext)	ISO 25,600 (102,400 ext)
Maximum frame rate	5fps	5fps	6fps
Autofocus	61 point, of which 41 are cross type and 5 are double-cross type	61 point, of which 41 are cross type and 5 are double-cross type	61 point, of which 41 are cross type and 5 are double-cross type
Metering sensor	150k pixels (RGB+IR)	150k pixels (RGB+IR)	63 segment (RG/GB)
Optical low-pass (anti-aliasing) filter?	Yes	Self-cancelling	Yes
Uncompressed HDMI output	No	No	Yes
Headphone jack?	No	No	Yes
USB connection	USB 3.0	USB 3.0	USB 2.0

A series of features in the EOS 5DS and S R are ones we first saw in the EOS 7D Mark II. This includes the flicker detection function that warns you of lighting flicker and can synchronize the camera's continuous shooting so that it only fires at the brightest moments to ensure consistent exposure (rather than the constant variation you can otherwise get in such situations).
Two other 7D II features to make an appearance in 5D camera for the first time are the built-in intervalometer function that can be used to shoot time lapse sequences. And, as a first for Canon, these can then be combined in-camera to create a 1080/24p time-lapse movie.