[pixee]

I own Carl Zeiss 21mm Distagon ze and am extremely satisfied with it after using/tried almost all the Canon wa-lenses. Colour, contrast, and also bokeh are very pleasing. and the lens is super sharp even wide open. The difference between 24mm and 21mm in FF does not sound big, but it is. If aperture f1.4 is absolutely needed Canon 24mm f1.4 may be good, too.

Here is one test from the web:

http://www.the-digital-picture.com/Revie...eview.aspx