Few weeks ago I bought a Pentax K-x. It's smaller but more sensitive that Canon 20D. I shot some pictures about the half Moon with my new camera.
If you opened this picture in a new window (and enlarge it) can you see the chromatic aberration on the right side of the Moon. I can't reduce it, because the refractor doesn't have aperture control.
You can see the hot waves dance in this short video (of course it's made with K-x too):