I had a lot of quesition before I got the 10-22mm f/3.5-4.5. One of them is how much difference does the 10mm make versus, say, 12mm. I hear this question alot on the POTN too so I sequenced the test shots I took and put them on youtube. I hope this helps someone who is struggling with a decision.
http://www.youtube.com/watch?v=_2EYgOG46L0![]()

