This lens came as part of a package, so I ended up taking some shots with it, and was very impressed with the image quality. You don't here much about the older, slower M lenses, and I know this lens isn't regarded as one of Leica's best formulas. I like the small size and the 10 bladed aperture that makes almost perfect circles at all the f stops. I also like that it focuses to 24 inches on a rangefinder, with full parralax correction. I was so surprised at the quality, that I decided to check it against my 40 Rokkor and 50mm Summicron on a lens test chart just for fun. Wide open it wasn't bad, but it did not do nearly as well as the Summicron and Rokkor at the same f3.5/f4.0 setting. The sharpness got much better by f5.6. By f8, it was able to resolve over 70 lines per mm center and 60 edge, which was as good as the 40 Rokkor, and only slightly less than the 50mm Summicron. (By the way, these absolute numbers are not as important as the comparisons from lens to lens. Using a higher contrast light source and sharper film than the 100 speed slide film I used will raise all of these numbers up). Here's is where it got interesting. At the smaller f stops, f16 and f22, it still resolved 70 LPMM center and edge, while the f2.0 lenses both fell to 50 and 50. This makes it a very usefull landscape lens where you can get everything in very sharp focus at high resolution from about 3 feet to infinity. I think it performs at the small apertures significantly better than the more modern, fast lenses, which are optimized for f8 and wider. This fact was born out in my field tests of the lens as well, and I made a 16 X 20 of My 1960 red Alfa Spider parked out along a grassy ridge at f16 that almost looks like a medium format shot. I'm keeping mine! I'd like to here any comments about this lens or other "sleeper" Leica lenses or Leica mount lenses others are using and happy with.