I have the highly touted Tamron SP 17-50mm f/2.8 lens with an EOS 40D. I was taking some shots and when I zoom in 1:1 at the part of the photo where the camera was focused, I expect it to be pretty sharp.. but it's a bit fuzzy to be honest. I tried different f-stops.. 2.8, 8, 10, tried ISO 200, ISO 400. What else would contribute to this? Am I just expecting too much, maybe? I'll see if I can post photos later.