Leica's slim mountain telephoto — the 105mm f/6.3 Elmar, lightweight screw-mount glass.
The Elmar 105mm f/6.3, engraved as 10.5cm, is a slim telephoto from the early 1930s screw-mount Leica line, sometimes nicknamed the mountain-Elmar for its light weight and use in outdoor and alpine photography. It occupies the space between the 90mm and 135mm telephotos on the 39mm Leica Thread Mount.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 105mm focal length and a modest maximum aperture of f/6.3. The slow aperture allowed a compact, lightweight barrel in the brass-and-chrome construction of the period. Verify filter thread and whether an example is coated, as most are early uncoated glass.
The slow f/6.3 aperture makes this a daylight telephoto for landscape, travel and general distance work rather than low light or shallow-depth portraiture. Stopped naturally by its design, it gives generous depth of field, and early uncoated examples carry the lower-contrast look of pre-war Leitz lenses.
This is a relatively uncommon lens and values are collector-driven, with condition and originality mattering most. Check for haze and cleaning marks, any coating wear on the rare coated examples, and element separation; confirm the focus is smooth, the aperture blades are dry, and the rangefinder coupling is accurate. It adapts to Leica M via a 39-to-M adapter and to mirrorless with an L39 adapter.