This is currently the widest-angle lens you can get for Nikon DSLRs, other than a few fisheyes.  But that's not the only reason to take it for a spin. Reviewers have noted that it's sharp and well-built; and the focus is fast and quiet. And for such a reasonable price too. What more could you want?

COMPATIBILITY NOTE: This lens carries Sigma's "DC" designation. It will not deliver a full-frame image on a D3 or D700 camera.