My apologies if this has been asked before.
The 600D and 7D share the same sensor. If I put the same lens (say, my 17-40 f/4 L) in front of both cameras, and snap the same shot at the same time, I should get the same image, right?
Granted, the 7D has more niceties (sealed body, microfocusing, probably more shutter life, etc...), but I'm talking strictly the quality and characteristics of a single image. Am I thinking about this correctly, or am I missing something?
The answer to this question is actually very strange. Speaking strictly about Canon, they seem to put lower quality circuitry in their lower end cameras. So while the sensor is the same, the other components which also contribute to the image quality slightly aren't. In the end this leads to a slight performance difference between a lower end and a higher end body with the same sensor. I've tested this with the 50D and the lower end camera that shares the same sensor, the T1i, on 4 seperate models of each, all showed a slight difference in favor of the 50D bodies.
In the end the slight difference doesn't matter but this should make you feel better if you have an expensive body with the same sensor as a cheap body, or in my case I was on the fence between a T1i and a 50D and I went with a 50D in the end.