Originally posted by thibs Fa20-35/4 or a 18-35 poses no problem but a 24-35/2 does ? I can't understand you guys...
And it is not as if I was a big Sigma fan...
EDIT: same goes for Tokina 11-16 and 11-20.
I wouldn't get a FA 20-35 or an 18-35.
When I put a zoom on, it isn't because I need the fastest lens out there, it is because I want to cover several focal lengths moderately well. When you have the possibility of losing one stop to f2.8 but gaining significantly more focal lengths (24-70), I would usually choose the latter. If I don't need much flexibility, then I would just go with a prime.
I do think really wide zooms that have fast apertures do tend to have smaller zoom ranges (14-24, 11-16, etc), but I wouldn't consider this really wide, but rather a normal zoom with the only thing going for it being the f2 aperture.