I like to do two kinds of photography, 1) Photograph Aircrafts for which I use the 100-400 and 2) landscapes for which I always used to use the 10-22 on my 40 D and recently even for landscapes I started using my 70-200 2.8 is since it allows the F/32 which I find very useful to capture detailed landscapes. I really wish I could use the 10-22 was a EF mount and not a EF-s mount. It is a beautiful lens and I would have loved it on the full frame.