Ultra-wide-angle lens made by Nikon, the Nikkor-O 21mm f4 for the Nikon S series. Introduced in 1959. 4 groups, 8 elements construction. Serial number 621xxx. The first three digits are dummy numbers.
While the Nikkor 21mm for the Nikon F is relatively common on the market, this Nikon S-mount version was produced in extremely limited numbers, with only 298 units said to have been made. Distance scale in meters. Filter size is 43mm.
The dedicated finder comes with its original box. 5 groups, 5 elements construction. Serial number 600xxx. Made of lightweight plastic. The dedicated deep rear cap is also included, featuring a mount to secure the finder. Rare item.

This lens was previously sold by our shop and has now found its way back to us after being carefully cherished by its owner.
There are no visible mounting marks on the bayonet, and it remains in exceptionally beautiful condition, just as it was when we last sold it. One could almost believe it to be a brand-new example from the period.
Fully overhauled in 2024. Thanks to the careful servicing, all operations remain wonderfully smooth today. It is in excellent condition for enjoyable shooting, though it may almost be too beautiful to actually use(笑)
The optics show some coating deterioration on an inner element, along with two or three extremely faint cleaning marks on the rear element, but these should have no noticeable effect on actual image quality.
Included are the dedicated finder with matching original box (serial 600xxx), the dedicated 21mm rear cap and leather case, an L38 43mm filter, and the front cap.
A highly desirable set combining rarity, superb condition, and rare accessories all together in one remarkable package. All that remains is to track down the ultra-rare dedicated hood.