Ah, well. I think I've decided on the Tokina 11-16 f/2.8.
-ginger
agreed. Although I LOVE my sigma 50 1.4, I thought it was WAY too long for my 40D 1.6x cropped camera. Now that I have a 1.3x crop 1D Mark II, I think it's the perfect focal length!
You should check out sample images of the ultra wide angle lenses. If you plan to shoot people, UWA's isn't probably what you want. Except for the center of the frame, the photos to the left, right, top, and bottom are going to look stretched and distorted, which makes people look distorted. UWA's are usually for real estate or landscape shots. If you buy the Tokina, I can almost guarantee that you'll be using the 16mm side of it close to 90% of the time. You might as well save some $$$ and invest in a good flash and the affordable 18-55 VR lens and your photos will come out significantly better.
Here's an example of a shot with my 16-35mm on my 1.3x crop body (equivalent of 13mm on 1.6x crop):
http://minihp.cyworld.com/36087945/1524060946
Notice how the photo seems a bit stretched on the edges and the woman to the left is distorted and unflattering.
(I only took the shot this way because I wanted that effect to focus on the child)
Like I suggested above, the 18-55 VR kit lens might suit you well. It's not ultra wide, but it's still a wide angle lens that is very capable in cramped spaces. It might not have the wide aperture of the Tokina or the Tamron 17-50, but if you'll be shooting in extremely difficult lighting situations like clubs, there's no lens that will be fast enough to capture the shot. Flash, if used correctly will do wonders, no joke!
































