I currently have a 20D that I'm looking to use as a second camera. My primary will most likely be a 50D or a T1i. I love the features of the 50D, primarily because I will need an ISO that produces quality photographs way beyond the 20Ds 1600. However, the HD feature of the T1i would be nice and this camera is better priced for me. My question is, how is the quality of T1i's high ISO? For a semi-professional, would anything in the Rebel line be suitable for studio, event, and fine art photography?