I thought this was a very informative post on another forum
It shows the D800 and 5D mark iii are much the same in night time type images despite the expectation that the 5D mark iii would be better.
If anything the D800 shows a slight advantage in that vertical banding shows up in the 5D mark iii when pushed hard and the D800 shows more detail when pushed hard.
You wouldn't call it in this example much of an edge though. But it is surprising that the Nikon does so well with 63% more pixels.
It would appear Sony is several years ahead of Canon in sensor technology. High megapixel/low noise high ISO performance seems unobtainable from Canon with their current technology.
http://forums.dpreview.com/forums/re...ssage=41012886
Greg