1. if I'm not totally daft the EF-S lenses are designed for APS-C. So does the 1.6 factor still apply?
2. need/want a wide angle zoom PDQ and something like 10-20mm and budget certainly won't stretch to Canon glass at present so looking at alternatives SIgma/Tamron etc. Anyone like to comment/recommend?
I've been using 60D for about 18 months, very happy with it and producing (in my opinion) some good images with it. Main lens I use is the Sigma 10-20 which I also think is good quality. Have a few images uploaded here which are mainly taken with that combination. Buy and enjoy.