I was just playing around with my cam at home shooting @ 2.8 and 8.0 focused on the same subject and the shots @ 2.8 are pretty damn soft. I don't know if this is normal for this lens or if it's something wrong with mine. Cam: XSi Lens: TAMRON 17-50/2,8 Tripod: Yes ISO 200 Focal length: 50mm One focus point, just above one of the letter (I think above the "S"). Here's a sample F 8 / 100% Crop F 4 F 2.8 Should it really be this soft? Please if you can, I would really appreciate if you could post shots for comparison.