When comparing Nikon D810 vs Nikon D5, the Slant community recommends Nikon D810 for most people. In the question“What are the best full frame DSLR cameras?” Nikon D810 is ranked 1st while Nikon D5 is ranked 2nd. The most important reason people chose Nikon D810 is:
It's fast and decisive both in good light and in low light. It accurately recognizes faces and focuses on the nearest eye.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Great autofocus
It's fast and decisive both in good light and in low light. It accurately recognizes faces and focuses on the nearest eye.
Pro Flat color profile for video
A flat color profile captures footage in low contrast and higher dynamic range allowing for easier color grading in post-production.
Pro Quiet
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 Durable
Pro Great high ISO imaging capabilities
Cons
Con Settings banks don't save all settings
Certain settings including AF and Advance modes can't be saved to settings banks and thus can't be recalled.
Con Lacks peaking for video
Focus peaking is not present in D810.
Con Poor AF in video mode
Con Subject tracking starts having issues in burst mode
Con Low-light performance could be better
Con Electronic 1st curtain can only be used in Mirror Up mode
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.
Con Single-purpose
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.