You can see my full comparison between these two awesome cameras here: Canon 70D vs Nikon D7100 Comparison Video
Lets play a game. Here is a chart showing 2 cameras, one is the new Canon 70D
the other is the Nikon D7100
Both cameras were using their respective 24-70 2.8 lenses; Canon 24-70 2.8L
and Nikon 24-70 2.8 ED
I shot a color chart, hand held, in fluorescent light, with AWB on both cameras, standard ISO noise reduction turned on.
Starting at ISO 400. I then doubled the ISO to 800, stopping down my aperture 1 full stop to compensate for it and repeated the process until I reached 12800.
I then stacked and cropped at 100% for close inspection. Which do you think is better? Each camera is labeled in it's respective column on the bottom of the chart.
More to come!
Subject Matter is also quite important. Take a look at these low light candle tests: