Canon has a serious gap in UWA lenses
why not a 16-35 f/3.5 4.5 like the EF-S 10-22 ?
why not a 14-24 2.8 or f/4 ?
why not even wider such as 12mm ? its a shame Sigma has one, and neither Canon and Nikon hasn't.
The ef-14mm 2.8 is really a bad lens, it needed more aperture blades and its way too expensive..
Thats why many canon users use nikon's 14-24 with an adapter for landscape photography. Cheaper, zoom, and same sharpness or even better i've heard, or a samyang 14mm which is a VERY cheap and VERY sharp and very usable. Best value for money no doubt!