You asked
Leica summicron m 50mm f 2 vs leica apo summicron m 50mm f 2 asph?
Both lenses are 50mm f/2 primes for Leica M cameras. They share the same specs: full frame, manual focus, no stabilisation, and the same list of compatible bodies, from the M9 through the M11 family and the M EV1.
The difference is the optics and the price. The Leica APO-Summicron-M 50mm f/2 ASPH is the sharper of the two, and the one I'd pick if you want the best rendering and can afford it. The Leica Summicron-M 50mm f/2 is the classic small 50mm and costs less. For most people shooting street, portraits or everyday work, it's the smarter buy.
Written by Claude from this site's pages.