# Nikon S-mount

The Nikon S-mount is a type of interchangeable lens mount used by a series of Nikon 35 mm rangefinder cameras (Nikon I, Nikon M, Nikon S, Nikon S2, Nikon SP, Nikon S3, Nikon S4). The lenses were sold under the name Nikkor.

## Technical details

The mount was a mechanical copy of the Zeiss Ikon Contax rangefinder mount, however, small differences between the two mean that although Zeiss wide-angle lenses can be used on the Nikon cameras and vice versa, the longer lenses (50 mm and above), if used, will not be able to focus at both close range and infinity.
Nikon made a small number of longer focal length lenses specifically designed to focus properly when mounted on a Contax. These were the 85 mm, 105 mm, and 135 mm lenses. Each was marked with a "C" on the side of the lens barrel. This is not to be confused with a "C" mark used as a suffix to the serial number. Some early Nikkors used this mark to denote that the lenses were coated.
The mount itself has two bayonets, one inside the camera and another outside. The body has a built-in focusing extension for lenses that use the inside bayonet, so these lenses do not need to have a focusing helicoid built into the lens barrel. As a consequence, the 5 cm f/1.4 lens that was normally sold with the body is extremely small (about the size of a golf ball) since the lens contains only the optics and aperture. Focusing of such lenses could be done by rotating the toothed wheel on the top front of the camera body or by rotating the lens barrel itself (the distance scale is on the camera body). The external bayonet is used to mount longer and heavier lenses where the built-in helicoid would not be strong enough to rotate the lens barrel. Such lenses are focused using a focusing ring and distance scale on the lens just like typical interchangeable lenses; the distance scale on the camera body is covered by the lens flange and thus is not visible when the external bayonet is in use.

## Lenses

Nikon produced a large range of Nikkor-branded lenses for these cameras with focal lengths ranging from 21 mm to 1000 mm. Several other manufacturers including Fuji (now Fujifilm), Komura and Zunow made S-mount lenses at the time of which the Zunow 5 cm f/1.1 lens is a keenly sought after collectors item. In 2002, Cosina Voigtländer manufactured a camera with a S-mount, the Bessa R2S, as well as several lenses for the Nikon S-mount.
In general, wide-angle Nikkor lenses with S-mount will mount directly to Contax bodies. 85 mm to 135 mm lenses were sold with special Contax mounts. In addition, most of the lenses were available as optically-identical versions with M39 lens mount. The 135 mm f/3.5 lens was additionally available in a version with a Kine Exakta mount.
Nikkor S-mount lenses :
| Name | Basic statistics | Basic statistics | Basic statistics | Basic statistics | Min. focus | Filter (mm) | Dimensions | Dimensions | Notes / Refs. |
| Name | FL (cm) | Ap. | Const. | I/E | Min. focus | Filter (mm) | Φ×L | Wgt. | Notes / Refs. |
| Ultra wide angle lenses ||||||||||
| Nikkor-O | 2.1 | f/4.0 | 8e/4g | E | 91 cm (36 in) | 43 | 55.8×53.5 mm (2.20×2.11 in) | 127.5 g (4.50 oz) | Biogon-type; final lens introduced for S-mount (1959). |
| Wide angle lenses ||||||||||
| W-Nikkor | 2.5 | f/4–22 | 4e/4g | E | 91 cm (36 in) | Ser.VII | 55.8×31.8 mm (2.20×1.25 in) | 126 g (4.4 oz) | Topogon-type |
| W-Nikkor | 2.8 | f/3.5–22 | 6e/4g | E | 91 cm (36 in) | 43 or Ser.VII | 55.8×32.4 mm (2.20×1.28 in) | 145 g (5.1 oz) | Orthometar-type |
| W-Nikkor | 3.5 | f/1.8–22 | 7e/5g | E | 91 cm (36 in) | 43 | ? | 160 g (5.6 oz) | Double Gauss-type; introduced 1956. |
| W-Nikkor | 3.5 | f/2.5–22 | 6e/4g | E | 91 cm (36 in) | 43 or Ser.VII | ? | 200 g (7.1 oz) | Double Gauss-type |
| W-Nikkor | 3.5 | f/3.5–22 | 4e/3g | E | 91 cm (36 in) | 43 or Ser.VII | 55.8×32.4 mm (2.20×1.28 in) | 190 g (6.7 oz) | Tessar-type; early versions stopped down to f/16. |
| Stereo-Nikkor | 3.5 | f/3.5–22 | 4e/3g (×2) | I | 91 cm (36 in) | 43 or Ser.VII | ? | 198 g (7.0 oz) | Stereoscopy lens capturing two half-frame (18×24 mm) images per frame. |
| Normal lenses ||||||||||
| Nikkor-N | 5 | f/1.1–22 | 9e/6g | E/I | 91 cm (36 in) | 62 | ? | ? | Double Gauss-type; introduced 1956 with internal bayonet; external bayonet production started 1958. |
| Nikkor-S | 5 | f/1.4–16 | 7e/3g | I | 91 cm (36 in) | 43 or Ser.VII | ? | ? | |
| Nikkor-S | 5 | f/1.5–11 | 7e/3g | I | ? | 40.5 | ? | ? | Short production run from 1950. |
| Nikkor-H | 5 | f/2–16 | 6e/3g | I | 91 cm (36 in) | 40.5 or Ser.VI | ? | ? | Sonnar-type |
| Micro-Nikkor-P | 5 | f/3.5–22 | 5e/4g | I | 91 cm (36 in) | 34.5 or Ser.VI | ? | ? | Xenotar-type; min. focus distance reduced to 45 cm (18 in) in extended position. |
| Nikkor-Q | 5 | f/3.5–22 | 4e/3g | I | ? | ? | ? | ? | Tessar-type collapsible lens; short production run from 1946. |
| Portrait lenses ||||||||||
| Nikkor-S | 8.5 | f/1.5–32 | 7e/3g | E | 107 cm (42 in) | Ser.VIII | ? | ? | Long focus |
| Nikkor-P | 8.5 | f/2–32 | 5e/3g | E | 107 cm (42 in) | 48 or Ser.VII | ? | ? | Long focus, Sonnar-type |
| Nikkor-P | 10.5 | f/2.5–32 | 5e/3g | E | 120 cm (47 in) | 52 or Ser.VII | ? | ? | Sonnar-type |
| Nikkor-T | 10.5 | f/4 | 3e/3g | E | ? | ? | ? | ? | Cooke triplet-type; introduced 1958. |
| Nikkor-Q | 13.5 | f/3.5–32 | 4e/3g | E | 150 cm (59 in) | 43 or Ser.VII | ? | ? | Early versions stopped down to f/16. |
| Nikkor-Q | 13.5 | f/4 | 4e/3g | E | ? | 40.5 | ? | ? | Tele-Sonnar-type |
| Nikkor-Q | 13.5 | f/4 | 4e/3g | E | ? | ? | ? | ? | Tessar-type; short mount (no focusing helicoid) version released in 1958. |
| Telephoto lenses ||||||||||
| Nikkor-H | 18 | f/2.5–32 | 6e/4g | E | 2.1 m (6.9 ft) | Ser.IX | ? | 1.7 kg (3.7 lb) | Uses prism reflex housing; introduced 1953. |
| Nikkor-Q | 25 | f/4–32 | 4e/3g | E | 3 m (9.8 ft) | Ser.IX | ? | ? | Uses prism reflex housing; introduced 1951. |
| Nikkor-T | 35 | f/4.5–32 | 3e/3g | E | 4 m (13 ft) | Ser.IX | ? | 1.7 kg (3.7 lb) | Uses prism reflex housing; introduced 1958. |
| Nikkor-T | 50 | f/5–45 | 3e/3g | E | 7.5 m (25 ft) | 110 | ? | 8.5 kg (19 lb) | Uses prism reflex housing; introduced 1952. |
| Reflex-Nikkor | 100 | f/6.3 | ? | E | ? | 52 | ? | ? | Uses prism reflex housing; introduced 1959. |