Nikon's fast Sonnar-type standard — the seven-element Nikkor-S 5cm f/1.4, smooth rendering, in Leica screw mount.
The Nikkor-S 5cm f/1.4 is the fast standard lens of Nippon Kogaku's (Nikon) rangefinder line in the Leica screw mount, introduced around 1950. Nikon engraved focal lengths in centimetres, so 5cm equals 50mm. It replaced the f/1.5 as Nikon's brightest 5cm and became one of the best-known fast Nikkors of the rangefinder period, carried by many photojournalists of its day.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 50mm focal length and a maximum aperture of f/1.4. The -S suffix stands for Septem, from the Latin for seven, meaning a seven-element design in the Sonnar tradition. That seven-element construction is the product distinction the letter records. Other details should be confirmed against the particular version.
This Sonnar-derived fast 50mm has a known reputation for smooth rendering, with soft, gradual out-of-focus areas that flatter portraits and a glow wide open that firms up on stopping down. The f/1.4 aperture makes it a capable low-light and available-light lens, while the 50mm view keeps it useful for street and everyday photography. Its character is a large part of its lasting appeal.
The Nikkor-S 5cm f/1.4 is among the most collected Nikon rangefinder lenses and clean, haze-free examples are actively sought, so condition strongly affects value. Inspect the glass for haze, fungus, separation and cleaning marks, and check coatings for scratches. Confirm the aperture blades are dry and the focus feels smooth. With an LTM-to-Leica-M ring, and a further adapter, it mounts on Leica M and mirrorless bodies, where its wide-open look is easy to enjoy.