Released in 1977, the Noct-Nikkor shown here is the AI-S version updated in 1982. It is a fast large-aperture lens of modified double-Gauss design with 5 groups and 7 elements.
This example is the famous mis-engraved version, marked Nocf-NIKKOR. The t and f were mistakenly swapped, resulting in the rather tongue-twisting nickname Nocf-Nikkor. A true oddity.
Such error engravings are very rarely seen on Leica products as well, and collecting them can be part of the fun.
The Noct-Nikkor was an ambitious project, employing high-refractive-index glass along with an aspherical front element to address sagittal coma flare at wide apertures. From manufacturing through inspection, it was reportedly produced without sparing any expense.
It would be fascinating to compare its rendering with other fast lenses. Although the rear element is protected by a guard, the glass protrudes slightly beyond the rear of the barrel, so careful handling is required.
The correct hood for this lens is the spring-loaded HS-7.

The lens shows an exceptionally clean appearance with virtually no signs of use. There are no noticeable mounting marks on the mount surface.
It was overhauled in 2023 by Kiitos for the previous owner. Both the aperture ring and the focusing helicoid operate smoothly and precisely. The glass shows a very slight area of coating deterioration, approximately 5 mm in diameter, at the center of a middle element, but this should have virtually no effect on actual images. Aside from this, there are no cleaning marks or haze, and the glass remains beautifully clear.
The HS-7 hood and front and rear caps are included. The hood shows some light signs of use.