Have been reading lots of lens reviews and note that some canon lens get a better review on the 30d than they do on the 50d, as a 50d owner just wondering how much difference does the sensor model make to IQ or is it just another "myth" like soft lenses
interested in your thoughts
I think the answer is that it's not a simple question.
But certainly, pixels don't make nearly as much difference as you might think in terms of sharpness. As I discovered myself when resolution testing a 40D (10mp) against a 7D (18mp) where there was nowhere near an 80% improvement.
Yes, the 7D was better, but not much and it was the improvement in noise that was most noticeable, and only that when you looked very closely. In other words, the amount of light captured and the way it's processed is often the most significant part of a new sensor, but it's always the higher pixel count that grabs the headlines.
However, at the same time I tried a 5D2 which has 21mp - hardly more than the 7D - but the difference was dramatic - sharpness, noise, dynamic range, contrast, everything. The reason for that is the sensor is more than twice the size, more than double the light gathering area, and the lower degree of magnification required means the lens doesn't have to work so hard. All round better result, and bigger always equals better in these things.
Have a look here on The Digital Picture where you can load up resolution test comparisons of the same lens taken with numerous different cameras of various formats and pixel counts
http://www.the-digital-picture.com/...meraComp=673&SampleComp=0&FLIComp=0&APIComp=0 The lens is the Canon 200L f/2, which was I think the sharpest lens they had ever tested at the time.
