Depends which M lenses you use and of course the film too. I've found that using Kodak tech pan(soon to be discontinued) with a DR 50mm provides outstanding results with unbelievable resolution. Much better than the present day asph lenses which seem too contrasty on the whole for high resolution B&W. The much touted version 4 35mm f2 is excellent in this regard too. The DR 50mm is similar to the Rolliecord Xenar in look and feel which is another stellar performer at f8, much better than my late Rollieflex Zeiss Planar 3.5 although the 3.5 is better wide open. I dont believe there is a better looking lens for resolution than the 50mm DR summicron in the M line. The now defunct magazine Modern Photography listed the Leica DR 50mm as the highest resolution lens they had ever tested. Emile.