Nippon Kogaku Japan Nikkor-N 5cm F1.1 External Mount rangefinder lens.

The use of the external bayonet required that the new lens have its own focusing helix individually cut for each lens. The internal version used the helix built into the camera body itself fore coupling to the rangefinder cam. Using the external bayonet allowed for more accuracy , especially with heaver lenses like the telephoto’s and the F1.1 Nikkor. Nikon would never make a f1.1 lens for their reflex camera’s, getting only as close as f1.2 . Any lens of such’s size and speed, not to mention price, made over 40 years ago would qualify as extremely collectable today, and the 5cm f1.1 Nikkor-N in either mount is no exception.

Introduced : May 1959.

Apertures : f1.1—f22

Angle of view : 46˚

Elements : 9 in 6 groups.

Focusing range: 3 ft. to infinity

Filter size: Ø 62mm

Weight : 400 grams.

Quantity produced: 1547