The 5.0cm/50mm F2.0's

This lens which was first introduce with the original Nikon F was an entirely new formulation. It was far from an adaptation from the "S" series cameras since the rear elements of those "normal lenses" would have impinged on the mirror movement of the SLR body design embodiments. A less than completely appreciated fact is that while the hierarchy of design considerations of the shorter focal length rangefinder camera lenses goes something like: sharpness, contrast, f-stop, practicability, practicality....; the list for SLR camera design parameter priorities leads off with MIRROR CLEARANCE (a paramount consideration here that does not even enter into the design parameter considerations for non reflex type camera lens designs). Virtually all of the prior existing lens designs with focal lengths shorter than 85mm (8.5 cm) had to be scrapped upon the advent of the SLR era.

The first 50mm (5cm) f2.0, the Nikkor-S

The very first of these 5 cm lenses, which began with SN 520001, had a Red R marking the offset for infrared focus. Also, the very earliest, a feature shared with the rangefinder lenses, had "TICK MARK" line markings both for "F" stop and distance units.



This earliest variation had a "PEARL" like finish, shared with several others of the earliest lens variations and brought on by very heavy chrome plating and subsequent lacquering:



The second and last significant variation of this lens (and these changes came on incrementally since Nippon Kogaku was known to be a very frugal company and changed versions as it used up existing parts) has no line "TICK MARKS" and the "R" mark for infrared offset was replaced by a red dot. It is very likely to find singular transitional lenses with only some of the original "TICK MARK" lens features:



Production of this lens Version ceased January 1964 with serial number 584394 .

Version 2:



Early 5cm lens shown with two early 50mm's

At the end of 1963 the F=50mm Nikkor-H was introduced to replace 5cm F2 . This lens redesign which was aimed at lower costs of production had a number of obvious and less than obvious economies of production incorporated:

The second optical formulation: The 50mm f2.0 Nikkor-H

This lens family, which had at least 5 versions and iterations, turned out to be so highly successful that it spanned production years to 1978 when it was to be replaced by a derivative 6element/5group F1.8 formulation:

The earliest, and collectible, version of this, starting with SN 6000001 had a very narrow (and awkward) scalloped focusing grip ring but no scallops (also awkward) in the aperture ring, smooth mounting surface, and had blue lens coatings; and, as Nikon was known to do, the earliest production used up remaining assembly parts originally destined for the previous generation/variation. The pictured example has a relatively bright center barrel coupled with a noticeably duller, later generation forward filter barrel/rim.

early Version 2

The second iteration of this lens, which carried it through SN 636XXX in June 1967, had evolutionary modifications aimed at handling, cosmetics, and simplicity of assembly and disassembly:

1. The focusing ring was made larger and easier to grip.

2. The aperture adjust ring was made scalloped for ease of gripping.

3. The NKJ identification was changed to Nikon.

4. "No. prior to the SN was dropped.

5. The lens mounting surface went from smooth to having 5 bolt heads.


Version 2a

Some of these changes were, as Nikon is often wont to do, progressive and phased in over the life of this version, so anomolous combinations are possible.

Serial numbers of these ranged from 600001 to 636021 (at least)

Another version with minimum deviation and SN's from 742111 to 2127000 took this variation to November 1972.

Version 3: The next evolutionary version of this lens marked the introduction of early NIC (Nikon Integrated Coating, Nikon's trademarked name for Multi-Coating) and was indicated by a DOT "C" after the "H" on the front of the lens and a black filter ring.



An interesting side note is that this was the third confusing application of the "C" designation on Nikon's lenses. The first two date back to its rangefinder lens design days when a DOT C on the lens front denoted a "HARD" non-reflective optical coating at a time when this was a novel engineering step that not all lens makers employed in all of their lenses. Approximately the same time Nippon Kogaku (Nikon's precedent corporate name) which had been producing lenses largely for Contax and LTM (also called Leica SM) started to produce its own rangefinder camera with an almost identical mount to the Contax mount. To differentiate which lens was for which mount, Nippon Kogaku placed a 'C' on the lens barrel side. This designation becomes especially confusing when one realizes that Nippon Kogaku's earliest and most sought after lenses, like the famous early Nikon rangefinder lenses were explicitly Contax mount and had no 'C' on the side. It can be argued that Nikon should have placed an 'NK' or 'NKT' on the side of lenses intended for its mount instead or in addition.

Version 4: The penultimate version of this lens was the RIFR (rubber insert focus ring) with a more greenish lens NIC and had SN's ranging from 3100001 to 3500000 in 1979.



Version 5: The RIFR was altered somewhat in appearance and an AI coupling was being incorporated for the fifth and last version prior to the introduction of the 50mm f1.8 .