I have heard that zoom lenses yield lower quality pictures. What exactly is worse about a picture taken with a zoom lens? Does anyone have an example? I was looking at some telephoto lenses today. I would like something to shoot people sailing at my club, as well as other stuff on the water. Usually it is pretty bright out, so I was thinking of getting a slow zoom, because the distance boats are away from me change. I was also thinking I could get a somewhat faster prime lens. I figure with 8 megapixels (XT, EF(S) mount), I can just crop out shots of things too far away, and I would also have the advantages of a wider max aperture. So what are the pros and cons of prime and zoom telephotos? Suggestions? Thank you!!