You asked
Leica noctilux m 35mm f 1 2 asph vs voigtl nder nokton vintage line 35mm f 1 5 aspherical?
The main difference is the aperture. The Leica Noctilux-M 35mm f/1.2 ASPH is the first 35mm Noctilux, and its f/1.2 opening gives you more light and shallower backgrounds. The Voigtländer Nokton Vintage Line 35mm f/1.5 Aspherical is a half-stop slower on paper, but both are 35mm manual-focus primes for Leica M bodies, neither is stabilised, and both fit the same cameras.
If you shoot in dim rooms or want the most separation from the background, the Noctilux is the one to pick. If you want a 35mm for everyday walking-around shooting and don't need the extra speed, the Nokton makes a lot of sense. A 35mm is a good choice for environmental portraits, and you can check where it sits on the focal length scale before you commit.
Written by Claude from this site's pages.