Nikon's rangefinder 28mm wide — the W-Nikkor 2.8cm f/3.5 in Leica screw mount.
The W-Nikkor 2.8cm f/3.5 is a wide-angle rangefinder lens made by Nippon Kogaku (Nikon) in the Leica screw mount in the early 1950s. Nikon engraved focal lengths in centimetres, so 2.8cm equals 28mm in modern nomenclature. It falls between the 2.5cm and 3.5cm wides in Nikon's early rangefinder range and was offered to users of both Nikon and Leica-thread cameras.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 28mm focal length and a maximum aperture of f/3.5. The W prefix marks it as a wide-angle Nikkor. The cm engraving reflects Nippon Kogaku's practice of the era. Additional optical specifications should be verified against the particular version rather than presumed, in keeping with accurate cataloguing.
A 28mm field of view is a classic reportage and travel width, taking in streetscapes, interiors and landscapes without the strong distortion of a wider optic. The f/3.5 aperture suits daylight and general use rather than dim interiors. Most rangefinder bodies of the day needed an accessory finder to frame 28mm accurately. Its modest size keeps a kit light for walking and travel.
These early wide Nikkors are collected by enthusiasts of Nikon rangefinder equipment and appear on the used market from time to time. Examine the glass for haze, fungus, separation and cleaning marks, and check the coatings for scratches under a light. Confirm the aperture blades are clean and oil-free and that the focus helicoid moves smoothly. With an LTM-to-Leica-M ring, or a further adapter, the lens can be used on Leica M and mirrorless cameras.