Nikkor-H 13.5cm 1:2 Prototype

The lens shown here is a prototype 135mm 1:2 lens, a faster alternative the the modest Nikkor-Q 135/3.5 which had been available since the early rangefinder days.

• The focal length is marked in cm (13.5cm) and the barrel is marked PAT. PEND. This suggests the lens was made in 1962 or 1963 at the latest. A very ambitious lens for Nikon in the early days of the Nikon F, even preceding more modest fast telephotos such as the Nikkor-Q 135/2.8 (Dec 1965) and Nikkor-H 85/1.8 (Aug 1964).
• Filter size is probably 72mm, the first time this size is used on a Nikon lens. In the following years this became the "large standard" filter size, used by the Nikkor-P 300/4.5, Nikkor-UD 20/3.5, Nikkor-P 180/2.8 and others.
• The lens is marked Nikkor-H (H = Hex = 6 elements) so probably had a double-gauss optical design, rather like a scaled up Nikkor-H 85/1.8.
• This lens was likely too abitious for the technology and materials of the time so never went into production. The first Nikkor 135/2 did not enter the market until a decade later. Interestingly this lens is also a 6 element design, although not related to this prototype.