Both Canon and Nikon recently refreshed their compact body full frame cameras, and as such, comparisons between the Canon 5D Mark III and Nikon D800 are inevitable, even though each camera has slightly different target markets and pricing.
However, if you’re not invested into either of the two brands already, and you’re looking at buying one of these cameras, then Dave Dugdale from Learning DSLR Video has you covered with his excellent head-to-head comparison. Dave was looking at purchasing one of these DSLRs himself, so he picked up both cameras, put equivalent lenses on them and shot videos and photos side-by-side. The resulting comparison and video review features in-depth coverage of each cameras strengths and downfalls, and contains some very helpful information. For more of Dave’s thoughts, read his written comparison over on his site.