Leica APO-Summicron-M 50mm f/2 ASPH Lens Review
It offers near flawless performance. The lens doesn’t flare at all when pointed directly to bright light sources, including the sun. However, flares may occur when there’s strong side lighting. To avoid vignetting, photographers can go directly to f5.6. However, it is a fairly minor occurrence and won’t be noticeable in typical photography task.
Sharpness is excellent across the frame, including from wide open. Photographer can get subtle improvements until f4.0 and better results can be achieved when working with depth of field control aperture.