Quote Originally Posted by STL
I would be interested to know at which apertures (f-number) they did their tests. As the T1i has a Diffraction Aperture Limit of f/7.6, testing the camera even at f/8 would reduce sharpness due to diffraction.

They did their tests at a variety of f numbers. The measurement of sharpness was number lines resolved across the whole picture. Diffraction is not an issue here.


Quote Originally Posted by STL
I think that it would be a good idea for Canon (and other SLR manufacturers) to stop cramming more pixels in sensors, as even though your picture is bigger, the increased diffraction can be a serious problem if you require a big depth of field.

Since they tested lines per whole picture, more pixels could only do better, not worse, than fewer. Diffraction is not changed by increased resolution. Diffraction gets worse only when you stop down.


Quote Originally Posted by STL
As a XTi owner, I think I'm gonna pass this one and maybe go with a used 40D when I'm gonna be able to afford it. The DLA is an issue for me, as I do macro shots and fireworks photography, which requires apertures between f/8 and f/11.

Macro would be one of the few cases in which I would think the new rebel would be superior to the 40D. It has better low noise performance and better resolution, both of which are important in macro since macro requires lots of light and since one tends to crop macro pictures. You'll be using manual focus most of the time, and probably won't care too much about super fast frame rate or responsiveness (thus much of the advantage of the 40d is negated). The rebel's superior screen will be of use for manual focus with live view.