Quote Originally Posted by Loupey
I never thought about it that way. The driving assumption is that each successive generation is going to improve/expand on the IQ of the lower range. I never heard of a successor camera within the same line that went backwards in this regard.
I think digital SLR image quality has reached the point where ISO 100 is excellent no matter what camera you're using. You really have to pixel peep to find any difference. And if you do, who cares? Because the only way those differences are going to matter is if you crop the living hell out of a photo. And if you're doing that, you've really missed the boat and it doesn't matter anyway.

As for cameras going backwards? I willl answer that possibility the same way. I think it's possible that low ISO image quality at the pixel level has decreased. I was very suspicious of that when Canon replaced the EOS 40D with the 50D. However, increased resolution oten makes it a wash. The bigger issue is whether we might have even better image quality if they'd just leave the resolution alone when they introduce a new camera.

Just to be clear - when I say "image quality" in this post I'm referring to noise. There are other things to consider like tonal control, color, etc. But noise is usually the thing people are most interested in.

Great thread, by the way!