Voigtlander's vintage-styled Heliar fifty for M — the APO-Lanthar 50mm f/3.5 compact design.
The Voigtlander Apo-Lanthar 50mm f/3.5 VM Type I is a compact collapsible standard prime from Voigtlander in Leica M bayonet configuration, representing a slower but more compact alternative to the f/2 Apo-Lanthar. The Type I designation and collapsible design evoke the traditional Leica Elmar collapsible lens aesthetic.
The lens delivers 50mm at f/3.5 maximum aperture with apochromatic optical correction, a collapsible barrel for compact storage, Leica M bayonet with 6-bit coding, rangefinder-coupled focusing, and full-frame coverage.
The collapsible f/3.5 Apo-Lanthar trades maximum aperture for extreme compactness — collapsed onto the M body, it reduces the camera profile dramatically for transport. The apochromatic correction at f/3.5 produces very clean rendering, particularly at f/5.6 and f/8 where the lens performs optimally.
Verify that the collapsible mechanism extends smoothly and locks correctly. Check rangefinder coupling accuracy. Test 6-bit coding. Inspect Apo-Lanthar element coating. Collapsed position must not be used for photography — only for transport.