Leica 50mm f/2 Summicron-M for Leica M9 Rangefinder
To my Guide and review of the Leica M9 I have added a 50mm f/2 Summicron-M discussion page and an examples page.
The 50/2 Summicron is an outstanding lens, one that I found very easy to shoot accurately and consistently on the Leica M9 (setting aside the composition hassles inherent to the frame lines on the M9 itself).
More coverage on the 50/2 Summicron is coming soon.
Aside from being very sharp, the 50/2 Summicron has near-zero distortion, which makes it ideal for photography of man-made objects where straight lines must remain straight. It also is excellent for landscape shots where a straight horizon is desired.