I'm think, or at least hope,it's partly the lens. I've got anXSi that I sometimes use an oldEF 75-300 f/4-5.6 II on and it seems to sap the life out of what could otherwise be a beautiful shot. It needs TONS of light (keeping in mind light doesn't weigh much []) My shots with my Tamron 17-50mm f/2.8 andCanon 50mm f1.8 II don't suffer from this problem. It's a slow, cheap lens I guess you get what you pay for.