Nikon's rangefinder telephoto — the four-element Nikkor-Q 13.5cm f/3.5 in Leica screw mount.
The Nikkor-Q 13.5cm f/3.5 is a telephoto rangefinder lens from Nippon Kogaku (Nikon) in the Leica screw mount, introduced in the early 1950s as a slightly faster companion to the f/4 version. Nikon engraved focal lengths in centimetres, so 13.5cm equals 135mm. It rounds out the long end of Nikon's rangefinder line with a brighter maximum aperture.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 135mm focal length and a maximum aperture of f/3.5. The -Q suffix stands for Quattuor, Latin for four, meaning a four-element design. That four-element construction is the product distinction the letter records. Other specifications should be verified per version rather than presumed.
At 135mm the lens gives telephoto reach for tighter portraits, candid work at a distance and detail shots, with the f/3.5 aperture offering a little more speed than the f/4 model. It separates the subject from the background well for its class. As with other rangefinder telephotos, an accessory finder helps framing and careful focusing pays off in sharpness.
This faster 135mm Nikkor is collected alongside the rest of the rangefinder line and shows up on the used market with some regularity. Check the elements for haze, fungus, separation and cleaning marks, and inspect coatings for scratches. Confirm the aperture blades are oil-free and the focus is smooth over its longer travel. With an LTM-to-Leica-M ring, plus a further adapter, it can be used on Leica M and mirrorless bodies.