Nikkor 13mm f/5.6

The Nikkor 13mm 5.6 is an ultra-wide angle rectilinear lens which was manufactured by Nikon for use on Nikon F mount cameras until 1998. It has been dubbed 'The Holy Grail', for its low-distortion ultra-wide capabilities. The lens was produced by Nikon only upon receipt of an order, thus making it one of the Nikon lenses with the least number manufactured.

Introduction
The lens was prototyped in 1973 and released on an 'order only' basis from March 1976. It was designed by Mr Ikuo Mori, First Optical Section, Optical Designing Department (now retired) and built in Japan.

Features

 * Very little distortion (less than typical 50 mm normal lenses) and lateral chromatic aberration.
 * Close Range Optical Correction (CRC) system: floating lens elements are used to reduce aberrations at close focusing distances.

Construction

 * 16 lens elements in 12 groups
 * Extreme retrofocus optical design with backfocus of more than three times the focal length.
 * Triplet/Tessar type master lens group behind the aperture.
 * Wide-angle lens group in front of the aperture to reduce the image size.

Versions

 * Nikkor F 13mm 5.6 - March 1976 (non-AI). Serial numbers began with:  175021.
 * AI Nikkor 13mm 5.6 - June 1977. Serial numbers began with:  175055.
 * AIS Nikkor 13mm 5.6 - March 1982. Discontinued in 1998. Serial numbers began with:  175901