Reflex Nikkor 50cm F5 Mirror lens . (1961). In case with filters.

This Catadioptric long focus lens has an unusual fast lens speed of f/5 while most of these lenses start at f/8. This early lens is not the fastest Nikon made but by quality a very good lens. Lens is very clean and complete.

Mount: Nikon F mount.

Picture size: 24x36mm.

Focal length : 500mm

Max aperture ratio : F5

Optical construction: 5 elements in 4 groups.

Minimum focus distance: 15meters to infinity

Filter mount: 39mm from the rear. 122mm from the front.

Lens hood : Screw-on type.

Dimensions : 125x 200mm

Weight: 1.6kg

By using a mirror design similar to that of a telescope. This lens uses very little glass compared to traditional telephoto lenses and is much smaller . lighter and far less expensive than traditional lenses in the same focal length. However this and all mirror lenses can produce a donut shaped bokeh in  the image it produces, which is usually undesirable.