Nikkor-S 5cm f1.4 from the Allied Occupation era. Tokyo engraving. White barrel. Nikon S internal bayonet mount. Serial number 316xxx. It belongs to the batch produced right after the dummy 5005 series. The manufacturing period is estimated around 1950 to 1951. This Nikkor was made during the Nikon M, MS, and early Nikon S period, likely when camera bodies still bore the Made in Occupied Japan (MIOJ) marking.
It is a Sonnar-type lens with 3 groups and 7 elements. Filter size is 43mm. At the time, it was the world’s first 50mm lens to achieve an aperture of f1.4, though it is often said that the actual brightness was closer to f1.5. At full aperture to around f2, it delivers a soft rendering, but stopping down to f4 transforms it into a sharply defined lens. In recent years, a variety of adapters for Leica and mirrorless cameras have become available, expanding the ways to enjoy this lens.

It has an exceptionally clean appearance for an item made over 70 years ago.
Fully overhauled in October 2025. The aperture operation is very smooth.
There are a few very fine, faint cleaning marks on the front element, but no haze.
Comes with the original box and genuine front and rear caps. The front cap is black-painted aluminum, and the rear cap is a later plastic type.