Canon's early Serenar rangefinder wide — 35mm f/3.5 in Leica Thread Mount, manual focus.
The Canon Serenar 35mm f/3.5 is a wide-angle rangefinder lens made in Japan for the 39mm Leica screw thread. Serenar was Canon's early lens brand, used on rangefinder optics from the late 1940s before the company shifted to the Canon name. This 35mm sits among Canon's first-generation screw-mount wides for Leica-thread and Canon rangefinder bodies.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 35mm focal length and a maximum aperture of f/3.5. The mount is the 39mm Leica screw thread (LTM / L39 / M39). Focus and aperture are set by hand on the barrel. Construction details such as element count, weight and filter thread are not restated here as they are not verified.
A 35mm focal length is a classic general-purpose wide for reportage, street and travel, close to the field of a normal lens but with more room in the frame. The f/3.5 aperture keeps the optic compact and best used in good light. As an early coated design it responds well to a lens hood to control flare.
On the used market these early Serenar wides show their age, so inspect closely for haze, fungus and balsam separation in the cemented groups. Check coatings for cleaning marks and wear, look for oily aperture blades, and turn the focus helicoid to confirm it is smooth. Verify rangefinder-coupling accuracy 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.