Nikon's fast rangefinder 35mm — the W-Nikkor 3.5cm f/1.8 in Leica screw mount.
The W-Nikkor 3.5cm f/1.8 is a fast wide-angle rangefinder lens made by Nippon Kogaku (Nikon) in the Leica screw mount in the late 1950s, near the end of the rangefinder era before the SLR shift. Nikon engraved focal lengths in centimetres, so 3.5cm equals 35mm. It was the fastest 35mm in Nikon's rangefinder line and a notable optic for available-light work of its day.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 35mm focal length and a maximum aperture of f/1.8, unusually bright for a wide-angle of the period. The W prefix marks it as a wide-angle Nikkor. The centimetre engraving follows Nippon Kogaku convention. Detailed optical construction should be confirmed for the specific example rather than assumed.
A fast 35mm suits street and documentary work in poor light, where the f/1.8 aperture lets the photographer keep shutter speeds up without flash. The wide angle still gives context around the subject. On period bodies an accessory finder framed the 35mm view. This combination of speed and width made it a favourite for photojournalists working indoors and after dark.
The fast 3.5cm f/1.8 is among the more desirable Nikon rangefinder wides and is actively sought by collectors, so clean examples command a premium. Look closely for haze, fungus, separation and cleaning marks on the elements, and check the coatings for scratches. Verify the aperture blades are oil-free and the focus is smooth and even. An LTM-to-Leica-M ring, plus a further adapter, allows use on Leica M and mirrorless bodies.