Stereo-Nikkor 3.5cm f/3.5

The Stereo-Nikkor 3.5cm f/3.5 is the rarest series-production lens Nippon Kogaku ever offered for its rangefinder system: a pair of matched 35mm f/3.5 optics mounted side by side in a single Nikon S bayonet, splitting every standard 36×24mm exposure into left- and right-eye half-frames that reassemble into three dimensions in the matching viewer. Introduced in December 1956 and built in one run of roughly 170 lenses, it turned an ordinary Nikon rangefinder body into a stereo camera — and it has since become one of the most valuable Nikkors of any era, a complete outfit bringing €48,000 at WestLicht and the companion viewer alone €18,600.

It was sold as an outfit rather than a bare optic: lens, hood, stereo prism attachment, stereo finder, 40.5mm L38 filter and fitted case came together for $274, with the stereo slide viewer a separate purchase. The twin lenses’ fixed separation gave orthostereo rendering — depth roughly as the eye perceives it — over a working range of about three to ten feet, and for subjects beyond ten feet, where the depth effect of a fixed base fades, the prism attachment extended the system’s reach.

The production history is unusually compressed, and the dates do not line up neatly: Pacific Rim Camera dates the release to December 1956, while Mikio Kuno (久野幹雄) — the source behind the ~170 figure — records actual manufacture across just March and April of 1957. Roland Vink’s serial database lists a single block, 241812–242062, dated May–June 1956: a 251-number span for some 170 lenses, a normal allocation overcount. However few were built, the lens stayed on the books for years — it remained available until late 1961. The optical construction, remarkably for a Nikkor, remains unconfirmed. The one spec table to publish a formula gives six elements in four groups per side, but the same table misstates the thoroughly documented Tessar construction of the ordinary W-Nikkor 3.5cm f/3.5, so the figure may be a table artifact — while a bare “four elements” claim circulates elsewhere online with no diagram or group count behind it, and no source settles the question either way.

No account of this lens is complete without the story that 28 unsold examples were destroyed before a tax official’s eyes, leaving “142 in private hands” — and none should print it as fact. It is lore: even its oldest online carrier, Pacific Rim Camera, introduces it with “rumor has it”; Japanese Wikipedia hedges both numbers as competing theories rather than record; the 142 is simply 170 minus 28; and the story’s modern viral retellings trace back to a single auction listing’s narrative. The solid figure is roughly 170 made; how many survive, nobody has counted.