Nikkor 1:3.5 f=5cm Nippon-Kogaku Nr.501xxx

These lenses have a modified aperture ring, with the aperture now on the side of the lens barrel where it is easier for the photographer to read when taking pictures. Otherwise these lenses are the same as the previous version. The serial numbers appear to follow on directly from the earlier 50xxx series. The style of the name-ring and serial numbers are similar to the 5cm 1:2 so they were probably made at the same time.
Related: « Previous | Next » | 5cm 1:2 | Home