Specifications:
focal length 58 mm.
The maximum aperture is 2.0.
The minimum aperture is 16.
Number of lenses/groups - 6/4.
The minimum focusing distance is 0.5 m.
Center/edge resolution - 38/20 lines per mm.
Number of aperture blades - 8
Light transmission - 0.82.
Type of enlightenment - single layer.
Mounting optics - threaded m42.