This is a popular vintage compact fixed-focus 50 mm prime lens made for SLR film camera with the K Mount. It was made in Japan by Asahi Optical Co. between 1975 and 1985, and weighs 138 grams. The maximum aperture is f2, the minimum is f22. It is a manual focus lens with a 6-blade iris. The minimum focus is 45cm, with a full-frame field of view of 47°, and when adapted to APS-C, has a 32° view. When adapted to modern digital cameras, this lens gets consistently good reviews for sharpness, aberrations, bokeh, handling, and value, and also has pleasant rendering as a portrait camera. It fits a 49mm filter.
This example is in fine condition, and includes a Vivitar Skylight (1A) filter and a hard plastic PK rear lens cap. The glass is clean with no scratches or fungus, and minimal internal dust. The iris blades are snappy, with no oil visible. This is a fun lens to adapt to modern digital cameras for stills or video work.