Originally Posted by macshark
40D was the first non-pro Canon DSLR to actually improve the image quality since 20D. At the time it was introduced, the 40D had much lower noise, much better dynamic range and colors and a better AF system and faster burst rate compared to any previous non-pro Canon camera. All of these were fundamental improvements IMHO.
Compared to what? A 300D? Any image quality improvement the 40D provided over the 20D/30D was marginal. Not much difference in the AF system, inferior colour, not a lot in it for noise, but about 1/3rd to 2/3rds of a stop behind the 20D. All in all, a lack-lustre camera, considering the superb standard set by the 20D. The biggest differences between the 20D and 40D were the self-cleaning sensor (at last!) and the bigger raw buffer (but I understand that the 30D already had provided this, though I've never owned a 30D to try it for myself).
The 50D, some would argue, continues this trend of ever-smaller image quality improvements. If the 15MP sensor was all there was to it, that woiuld be a fair enough point. Nevertheless, the 50D does
provide noticable IQ improvements over the 40D, and is the first mid-range Canon to be clearly
superior to the old benchmark model (as opposed to the 40D, which may or may not have been superior to the 20D - opinions differ - but certainly wasn't clearly and unambiguously superior.)
The 50D, however, combines this gain with an across-the-board refinement of almost every feature, even the things that stay essentially the same (like the menu system) have been fine-tuned. Taken as a whole, it is a much more satisfying camera than the 40D. And
where the light is decent and your lens is better than poor, it provides more detail.
What's not to like?