Roy, we all crop as much as we have to. Some of my published shots are 100% crops - not too many, but a few. I'm not for one moment saying that a 100% crop for artistic reasons is a bad thing (though of course it's better to avoid that if you can). The point here is that if you take the same shot from the same place of the same poor little bird with the same lens, and for artistic reasons you need to take a 100% crop from the 40D image to get your finished image, you will only need to take a 66% crop from the otherwise identical 50D image. Or, if the bird is so small in frame that you need a 100% crop from the 50D, then to print it at the same size from the 40D image you need to take a "150% crop" - i.e., enlarge the 100% 40D crop from (say) 640 x 480 to something like 800 x 600! And the result, of course, will be well below the quality of the 50D result either way.