Nikkor-N(·C) 5cm f/1.1

When the Nikkor-N·C 5cm f/1.1 appeared in February 1956, it was only the second lens in history to break past f/1.2. The first had come three years earlier from Teikoku Kogaku (later Zunow Kogaku), whose Zunow 5cm f/1.1 extended the familiar Sonnar concept — and Nippon Kogaku’s answer was pointedly not a Sonnar. Saburo Murakami (村上三郎), manager of the company’s 3rd Mathematics Section, built a nine-element, six-group design that Nikon itself describes as Gaussian, hanging its speed on three convex elements of newly developed lanthanum rare-earth glass. The design and prototyping took him two years, worked out with an abacus and a sheet of logarithms; the patent was filed in 1957 and granted in the United States the following year.

The lens’s production story is really a tale of two mounts. The original version — 835 made, serials 119601–121131 — used Nikon’s internal bayonet, which meant all of its considerable weight (over twelve ounces) rode on the camera body’s own focusing helical. The strain was real enough that internal-mount lenses went back to the factory for mount adjustment. Nikon redesigned the barrel in mid-1958, and from around June 1959 the external-mount Nikkor-N (1,547 made, serials 140701–142498, with early examples engraved “Pat. Pend.”) carried its own helical, so the front no longer rotates with focus. Either way the front is imposing: a 62mm filter thread, and an enormous hood that shipped with its own case and a 62mm UV filter.

Rarest of all are the 211 Leica-screw-mount lenses, all built on the internal-mount design — and, by expert consensus, interleaved within the internal-mount serial block rather than issued as a contiguous batch; no published lowest or highest LTM serials exist. The handful of serial-confirmed survivors form a tight cluster in the 1201xx range and now trade at five-figure prices. That cluster sits just above the most storied serial of all: 120155, an internal-mount lens reported as Che Guevara’s, mounted on his Nikon S2 and displayed at the La Cabaña fortress museum in Havana. The serials trace to a single first-hand forum lineage, so the attribution should be read as reported rather than confirmed — but it is a remarkable footnote for a lens this rare.

Nikon’s own retrospective essay on the f/1.1 ends with a fitting piece of lore: essay author Haruo Sato’s (佐藤治夫) personal example had been sitting on a desk as a damaged paperweight until master prototyper Kazuya Udagawa (宇田川和也) tracked down the original blueprints, repaired the diaphragm blades himself, and rebuilt the lens to specification — then promptly fell for the way it drew still lifes and portraits.