Canon's very fast rangefinder normal — 50mm f/1.2 in Leica Thread Mount, manual focus.
The Canon 50mm f/1.2 is a very fast normal rangefinder lens made in Japan for the 39mm Leica screw thread. Released in the mid-1950s, it was among the fastest 50mm lenses available for Leica-thread bodies at the time and remains one of Canon's most collected rangefinder optics. It gave Leica-thread and Canon rangefinder users a bright lens for demanding low light.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 50mm focal length and a maximum aperture of f/1.2. The mount is the 39mm Leica screw thread (LTM / L39 / M39). Focus and aperture are set on the barrel by hand. Element count, weight and filter thread are not restated here because they are not verified from the gap data.
At f/1.2 this is a specialist available-light and portrait lens, delivering very shallow depth of field and strong subject isolation. Fast fifties of this class render softly and with lower contrast wide open, often with visible glow and vignetting, then improve markedly on stopping down. Precise focus is essential given the razor-thin plane of focus at full aperture.
On the used market this is a desirable lens, so scrutinise condition against price: inspect for haze, fungus and balsam separation in the cemented groups. Check the coatings for cleaning marks and wear, look for oily aperture blades, and confirm the focus helicoid is smooth. Rangefinder-coupling accuracy is critical at f/1.2, so test it carefully on a body. It adapts well to Leica M via M39-to-M and to mirrorless with M39-to-E, M39-to-Z or M39-to-RF adapters.