sigma

My copy of this lens gives good image quality, though it does have slight barrel distortion (things near the edge of the field of view bulge out very slightly). This is typical for this wide of a lens, and isn't noticeable unless viewing something with lots of straight lines near and parallel to the edge of the frame.
I like the lens, but do make sure you really want a lens with a field of view THIS WIDE. It's nice for landscapes, but they will all have everything but the kitchen sink in each shot. You can't use this lens to isolate a particular feature of interest like you can with a standard or a telephoto lens.
One feature nobody seems to pay much attention to on this lens is that it can focus very close! You can do a sort of wide-angle macro work with this lens, if the light is good.
I recommend it as a relatively affordable alternative to the Canon or Tamron equivalents, if you are sure a 14mm lens is something you really want. I like mine, but occasionally have second thoughts about needing a lens this wide. Finally, I should mention that I use a digital SLR which only uses the central 2/3 of the lens. I've seen reports from others saying that edge distortion on this lens is unacceptable with a full-frame film camera.

To echo what is said about the new release SIGMA lenses - WOW.

Canon look out. I was shopping for a new toy for XMAS and settled on the CANON 14mm F2.8L lens. It was very nice but for the price hard to justify. I asked for an eval of the Canon and this, the Sigma alternative at 1/3rd the price. Head to head testing of the lenses on my Canon EOS 50 (ELAN) using ISO 200 film resulted in the Sigma producing a crisper image with better definition and colour saturation. Both lenses have a little "flattening" of the image at the edges as they try to compensate for curvature but the Sigma in my opinion is closer to true. Neither lens had any trouble Auto-Focusing during the day (Canon felt a little faster). The Sigma was a little unsure of itself on when I went for a night/bulb exposure of the starscape. Switched to Manual, set for infinity and away we went. My only other issue with the Sigma is the lens hood is not quite big enough where the Canon is spot on. Still you have to be looking really hard for faults to find them.

Tooling around with the lens has been lots of fun. I had never considered using the lens for indoors shots but it is magic. Architecture photography is going to be a new thing for me I think.