I personally wouldn't recommend a fisheye. In my opinion it's a tool for real specific jobs. If you don't plan to use it like that, I wouldn't have bought it.


The 21mm zeiss lens is probably very nice, but only manual focus and really not close to ultra wide on a crop body.


I would recommend a 10-..mm if you want an ultra wide which is still usable for other situations.


Once I read an article about different brands 10-xx lenses and the canon was clearly the winner compared to sharpness. The article is linked somewhere here on the forum. I only had the opportunity to shoot with the Tamron 10-24 which is a very nice lens if I must say. A review:http://www.dpreview.com/lensreviews/tamron_10-24_3p5-5p6_n15/It's also a bit cheaper than the canon, but lacks the ultra fast and silent autofocus.