You asked
Leica summicron m 28mm f 2 asph vs voigtl nder color skopar 28mm f 2 8 aspherical?
The Summicron-M 28mm f/2 ASPH is the faster lens. Its f/2 maximum aperture lets in about half a stop more light than the Voigtländer's f/2.8, which helps in dim streets and gives a little more background blur when you want it. Both are 28mm manual-focus primes for full-frame Leica M bodies, and both fit the same long list of M cameras, so the choice comes down to aperture and what you want to spend.
If you shoot in low light or want the most separation from the background, go with the Leica Summicron-M 28mm f/2 ASPH. If you want a 28mm for daylight street work and you'd rather keep the kit simple, the Voigtländer Color-Skopar 28mm f/2.8 Aspherical does the job. For more on why 28mm suits the street, see Street.
Written by Claude from this site's pages.