Canon's Serenar fast portrait tele — 85mm f/1.5 in Leica Thread Mount, manual focus.
The Canon Serenar 85mm f/1.5 is a very fast short-telephoto rangefinder lens made in Japan for the 39mm Leica screw thread. It carries Canon's Serenar branding from the early 1950s and stood among the faster portrait-length rangefinder lenses of its day. It gave Leica-thread and Canon rangefinder users a bright 85mm for low light and portraits.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with an 85mm focal length and a maximum aperture of f/1.5. 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 omitted here because they are not verified from the gap data.
At f/1.5 this is a fast portrait lens that isolates subjects with a shallow plane of focus and soft backgrounds. Fast short teles of this era render smoothly and with lower contrast wide open, sharpening as they are stopped down. It suits portraits and low-light work where the wide aperture and 85mm reach are both wanted.
Buying used, inspect for haze, fungus and balsam separation in the cemented groups, which are common in fast vintage teles. 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 for a fast 85mm, so test it carefully on a body. It adapts well to Leica M via M39-to-M and to mirrorless using M39-to-E, M39-to-Z or M39-to-RF adapters.