Any experience with Sigma 20/1.8?
I have owned it and i am satisfied. The IQ at 1,8 is sufficient for low light. Stopped down IQ is very good. In spite of its short focal length and its wide aperture you have to focus correctly. I normally use MF (with the D200 and Katz Eye), because AF doesn't work pecisely enough.
It is heavy, but well made. Not very lable to flare.