You asked
What are the alternatives to the leica apo telyt m 135mm f 3 4?
I don't have a list of other lenses that fit the Leica APO-Telyt-M 135mm f/3.4 on this site. Its page only covers the lens itself and the Leica M bodies it works with, so I can't name a specific substitute without guessing.
If you want a similar job done, the portraits guide is the best starting point. It suggests 85mm f/1.8 for classic full-frame portraits and a 135mm or 70-200mm f/2.8 for tight headshots with strong background blur. For a broader look at focal lengths, see the lenses guide. You can also browse lenses for your mount in the gear catalogue.
Written by Claude from this site's pages.