Nikon's rangefinder standard — the six-element Nikkor-H 5cm f/2 in Leica screw mount.
The Nikkor-H 5cm f/2 is a standard rangefinder lens made by Nippon Kogaku (Nikon) in the Leica screw mount in the late 1940s. Nikon engraved focal lengths in centimetres, so 5cm equals 50mm. It became one of Nikon's most widely used standard lenses of the rangefinder era, valued for a balance of speed, sharpness and compact form.
This is a manual-focus, rangefinder-coupled Leica Thread Mount lens with a 50mm focal length and a maximum aperture of f/2. The -H suffix stands for Hexar, from the Greek for six, meaning a six-element optical design. That six-element construction is the product distinction the letter records. Some versions were collapsible; that and other details should be confirmed on the specific example.
As a fast standard the 5cm f/2 handles everyday, street, travel and head-and-shoulders portrait work, with enough speed for shade and indoor light. The six-element design gives good sharpness stopped down while keeping pleasant rendering wide open. Its normal perspective and compact build make it a natural default lens for a rangefinder kit.
The Nikkor-H 5cm f/2 is a common and well-liked Nikon standard, so buyers have some choice, though clean coated examples are preferred by collectors. Inspect the glass for haze, fungus, separation and cleaning marks, and check the coatings for scratches. Make sure the aperture blades are dry and the focus turns smoothly. The screw mount adapts to Leica M with an LTM-to-M ring and to mirrorless with a further adapter.