Robin Good: Thanks to fellow video curator Philippe Gassmann I have run into this excellent blog review by DSLR News Shooter that compares the Nikon D800 and the existing king of the market, the Canon 5D MKIII.
"Before the advent of the Nikon D800 and D4 there was no choice if you wanted a full frame DSLR shooting 1080P video – it had to be a Canon.
This past week, I and several other members of the photo and video press and bloggers have been guests of Nikon Europe in New York on the “48 hour challenge”: getting our hands on production models of the D800 and being allowed to shoot what we wanted."
N.B.: The video pictured above is a side-by-side rolling shutter test of the Nikon D800 and Canon 5D mkIII at the Gleasons gym in New York. Do not use this clip to assess anything more than rolling shutter performance as the white balance and exposure are not optimally set for either camera.
More video comparison: