It's getting rarer these days to find the kind of specialist shops that have so much stock from years gone by that they're more like a mini-museum than a retail outlet. Grays of Westminster is just such an emporium. Exclusively dealing in products spanning the whole history of the Nikon Corporation, the award-winning central London curiosity shop managed to generate a huge online buzz this week by announcing the sale of an exceptionally rare monster of a wide-angle Nikkor lens. Said to allow cameras to actually snap images of scenery behind the lens and weighing in at 11.46 pounds (5.2 kg), the mint condition 6mm f/2.8 Nikkor lens has just sold for an equally gargantuan price of £100,000 (US$162,312) to an unnamed private collector.

Developed for use in scientific and industrial applications and special effects during portrait shoots, the 220° super wide angle – well, pretty extreme wide angle if truth be told – f/2.8 to f/22 aperture lens is said to have stunned attendees at the 1970 Photokina show in Cologne, Germany before going into very limited production two years later. Nikon's Jeremy Gilbert told the UK's Daily Mail that the rare lens dates back to a time when "lenses had to be designed with a slide rule and individual ray diagrams."

The lens – serial number 628024 – is constructed of 12 elements in nine groups, is fronted by a large glass dome that keeps the attached camera very much in its shadow, and comes with its own slip-on lens cap and rugged metal case. It's 9.29 inches (236 mm) in diameter and some 6.7 inches (171 mm) in length, has an automatic diaphragm, and its distance scale is graduated in meters from 0.25 meters (0.9 feet) to infinity. It also comes with skylight (L1BC), medium yellow (Y48), deep yellow (Y52), orange (O56) and red (R60) filters, and was sold together with a black Nikon F Apollo camera.

The company's founder Gray Levett said that the unusual fisheye lens was tracked down by vintage camera buyer Toni Kowal, who spent six months following leads abroad before securing its purchase.

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