I'm often disappointed by the quality of the images produced by my Cannon EOS Ti and I don't think I necessarily should be: It's a nice enough camera. I'm using the kit lens and I have two friends that have MUCH nicer lenses and they seem more content. Would purchasing a much nicer lens help satisfy my desire for higher image quality in any way? I take photography of people, outdoors, in full light. Senior photos, modeling portfolios, absurd photo illustrations and the like. I don't need anything specialty. Any suggestions?