Sigma 10mm, F:2.8 Fisheye for Canon
Crutchfield Customer Review (What's this?)
This lens is awesome. Though a third party product, I did not expect it to be very sharp. There is a very slight vignetting but it's negligible. It's gone after cropping. Can't complain. Am just an enthusiast using dslr and all the pictures taken with this lens are all very sharp, proven by viewing them in the computer. I'd recommend this to anyone.
Pros: Excellent in any situation.