Excerpt: I must agree with many of the others: the lens has a good feel, good handling of perspective, but there's significant vignetting and soft focus, even when placed on a tripod with remote shutter. I returned it to B&H after one week (my kudos to B&H for their courteous handling of returns).
Excerpt: I bought it to use with my Canon 5D Mark III for street photography and the occasional landscape. Very true colors and little distortion (nice) but serious vignetting, especially noticeable in the landscape shots.
Summary: I was really excited for this lens and I couldn't wait to use it for a family function. I don't consider myself a professional photographer but i am constantly using my DSLR and taking pictures but I was very disappointed with this lens, I am sending it back immediately.
Conclusion: I've had this lens for several years. The images are soft at all apertures. There's a color cast. There's massive vignetting, though PIC removes it pretty well. You'd be better served to save your money for the 17-40 zoom.
Cons: Semi-sharp images, color cast, intense vignetting
Summary: I used it to shoot from an elevated angle. The result were disappointing.....I paid $[...] but I don't think it is even worth more than $[...] to tell you the truth. The colors are lifeless, "burnt-out". There are no details on the images. You can see the samples on my site: [...
Summary: I wanted a 20mm prime to use for night shooting, so I thought I'd give this one a try. I chose poorly. Returned it the same day. Still on the hunt for a good prime night long exposure performer. This lens was really soft around the edges (even on my 40D with a 1.6x FOVCF).
Summary: The lens is okay on a 1.6 crop factor digital camera, but it isn't particularly wide-angle then (32mm field of view). I hear that it is okay on a film camera, but I have no experience. On a full-frame digital camera, it stinks...
Summary: I bought this lens to get a bit wider than The 28-135mm IS which was my first lens for the new 10D. I liked the reasonable size and that I could share the 72mm filters with the 28-135IS. I am not happy with the sharpness of this lens at any f/stop and will not use it at all wide open.
Pros: Low used price. I like the size and weight. I can share filters with my 28-135mm IS. I like the focal length.
Cons: This lens is not as sharp as I expect from a prime and is not as sharp as the 17-40L that I replaced it with.