When comparing Canon 5DS / R vs Nikon D5, the Slant community recommends Nikon D5 for most people. In the question“What are the best full frame DSLR cameras?” Nikon D5 is ranked 2nd while Canon 5DS / R is ranked 7th. The most important reason people chose Nikon D5 is:
D5 has 153 AF points of which you can select 55. 99 AF points are cross-type (of which 35 are selectable). 15 AF points work with f/8 lenses (of which 9 are selectable). The autofocus works down to LV -4. Autofocus is amazingly fast at 14 frames per second with top of the class accuracy (in tests performed by Tony Northrup it was only second to 1DX Mark II in terms of how many shots were in focus having just 6% fewer of shots be in focus).
Ranked in these QuestionsQuestion Ranking
Pro Flicker detection
The camera can detect flickering light sources and sync up with them to shoot at peak brightness in order to avoid underexposing the image by accident.
Pro Good autofocus system
61-point autofocus system with 41 cross-type points that performs well in low light. In addition, 5 central autofocus points turn into dual-cross-type points with fast (f/2.8 or faster) lenses increasing the precision even further.
Pro In-camera timelapse
Pro Excellent build quality
The 5DS/R has a magnesium alloy shell that makes it durable.
Pro Programmable Auto ISO
Pro Natural skintones
Pro High resolution
50.6 MP compared to 22.3 MP for the 5D Mark III.
Pro Advanced autofocus
D5 has 153 AF points of which you can select 55. 99 AF points are cross-type (of which 35 are selectable). 15 AF points work with f/8 lenses (of which 9 are selectable). The autofocus works down to LV -4.
Autofocus is amazingly fast at 14 frames per second with top of the class accuracy (in tests performed by Tony Northrup it was only second to 1DX Mark II in terms of how many shots were in focus having just 6% fewer of shots be in focus).
Pro Huge ISO range
D5 has a native ISO range of 100 to 102,400 which can be expanded from 50 to 3,280,000.
Pro Can automatically detect faces and focus on them
Pro Can shoot stills during video
Pro Great high ISO imaging capabilities
Con Limited video capabilities
No HDMI output, no headphone socket.
Con Dynamic range could be better
According to tests performed by DxOmark 5DS / R has 12.41 stops of dynamic range in print and 11.08 stops on screen for images taken at 100 ISO while cameras in this price range commonly push 14 in print and 13 on screen.
Con Low max ISO
The cameras go up to 6400 (or 12800 in extended) ISO.
Con AF subject tracking could be better
Con Low-light performance could be better
Con Images at base ISO nosier than competition
Con Image quality is surpassed by much cheaper cameras
Nikon puts D5's AF capabilities above everything else to the point where cameras that cost less than half the price (like Nikon's own D810) have clearer, sharper images with higher dynamic range and higher resolution.
It's an extremely specialized camera. Unless you're doing photography that involves fast moving targets, the camera's capabilities will not justify the price.
Con Internal 4K video capture is limited to 3 minutes
Fortunately video can be sent over HDMI to an external recorder.
Con Dynamic range of base ISO could be better
According to tests performed by DxOMark, dynamic range of the D5 is at ~9.35 stops for base ISO (50 to 100). Lowest of any FF Nikon DSLR.
Con 4K video has a 1.3x crop
Con AF in video mode is lousy
Con Lacks built-in Wi-Fi
Con AF point coverage could be better
Con Low resolution for a flagship
The camera is 20MP, D810, for example is 36.3 MP.
Con Not all AF points can be manually selected
Out of the 153 AF points only 55 can be selected.