Data Sheet: Nikkor Ai-s 105 mm f/1.8

Pekka Buttler, 12/2022 (Updated: 01/2024)

Pictured: Nikkor Ai-s 105 mm f/1.8

Specifications

The table below summarizes the lens’ key specifications (measurements based on pictured sample):

Brand:NikonLens nameNIKKOR 105mm 1:1.8
Focal length(s) 1105 mmAngle-of-view 223°20
Maximum Aperturef/1.8In Production1981-2005
Lens mountNikon FSubfamily (if applicable)Ai-s type
Length 380,2 mmDiameter 478,9 mm
Filter ring diameter62 mmWeight565 grams
Lens element count5Lens group count5
Aperture blades (S/R/C) 59Focus throw140 °
Minimum focusing distance1,0 mMaximum magnification1:7,6
Has manual aperture ringYESHas Manual focus ringYES
Aperture mechanism typeAutomaticAperture click stops 61.8-2.8-4-5.6-8-11-16-22

Further notes:
• Until the 2016 introduction of the Nikkor AF-S 105/1.4, this lens has been the largest-aperture 105 mm lens ever produced by Nikon.
• This lens was a unique product, and has only ever been produced as an Ai-s version.
• With roughly 40 000 copies, it’s a relatively rare lens.
• Alike many Ai-s lenses, this lens featured an integrated hood.
• As is plain to see, my copy has suffered a major collision, which – luckily – shows no optical effect.

A brief genealogy of Nikon SLR lens types

Nikon is undoubtedly one of the great names in 35 mm SLR photography. The Nikon F mount has been in continuous production since 1959. During that time, the mount has developed/changed in some detail, however without ever fully sacrificing compatibility.

In short (a longer version is here), the development of Nikon’s SLR lenses can be traced as follows:
• 1959–1977: Pre-Ai. Manual focus lenses that use ‘rabbit ears’ to communicate selected aperture with the camera body. Pre-Ai lenses can further be subdivided into
• F-type (1959–early 1970s: metal focus ring and single-coated),
• C-type (early 1970s–mid 1970s: metal focus ring and multicoated), and
• K-type (mid 1970s to 1977: rubber focus ring and multicoated).
A significant share of remaining Pre-Ai lenses have since been converted to Ai-spec (Ai’d)
• 1977–1986: Ai and Ai-s. Manual focus lenses that may have ‘rabbit ears’ for backward compatibility, but are designed to communicate selected aperture with the camera body through indentations in base of aperture control ring.
• 1986–today: AF and AF-D. Autofocus lenses that do not have a focusing motor within the lens, but rely on the focus motor within the camera. All AF and AF-D lenses are simultaneously Ai-s lenses (they are Ai-s lenses extended with AF) 7
• 1996–today AF-S and AF-P. Autofocus lenses that have an internal focusing motor and do not rely on the body having a focusing motor.

Versions

While the 105 mm f/1.8 was a unique product, it still ‘sits’ within a wider portfolio of lenses and optical designs. Throughout the 1960s and 70s Nikon’s main emphasis in short tele lenses was on the various designs of 105 mm. Only in the 80s did Nikon bow to peer pressure and supplant the various 105 mm short teles with the 85 mm short teles everyone else was doing. The table below will trace the development of Nikon’s offering in the 100-105 mm range (Micro/Macro lenses excluded:
• 1959–1971 105mm f/2.5 (5 elements in 3 groups, 6(9) blades, 1,2 m MFD, “Nippon Kogaku Nikkor-P”) (F-type) [data sheet]
• 1971–1973 105mm f/2.5 (5 elements in 4 groups, 7 blades, 1 m MFD, “Nikon Nikkor-P”) (F-type)
• 1973–1975 105 mm f/2.5 (5 elements in 4 groups, 7 blades, 1 m MFD, “Nikon Nikkor-P•C”) (C-type)
• 1975–1977 105 mm f/2.5 (5 elements in 4 groups, 7 blades, 1 m MFD, rubber focus ring) (K-type)
• 1977–1981 105 mm f/2.5 (5 elements in 4 groups, 7 blades, 1 m MFD, rubber focus ring) (Ai-type) [this lens]
• 1979–1985 100 mm f/2.8 (4 elements in 4 groups, 7 blades 1 m MFD (Series E lens] [data sheet]
• 1981–2005 105 mm f/2.5 (5 elements in 4 groups, 7 blades, 1 m MFD, rubber focus ring) (Ai-s-type)
• 1981–2005 105 mm f/1.8 (5 elements in 5 groups, 9 blades, 1 m MFD) (Ai-s-type)
• 1993–2020 105 mm f/2 DC (6 elements in 6 groups, 9 rounded blades, 0,9 m MFD) (AF-D type)
• 2016– 105 mm f/1.4E (14 elements in 9 groups, 9 rounded blades, 1 m MFD) (AF-S type)

Adapting

Besides adapting, this lens can be used natively on all current high-end Nikon dSLRs and several earlier medium-to-high-end older Nikon dSLRs 8. Likewise, if it still has its rabbit ears, it can be natively used on all Nikon F-mount film cameras ever produced (without the rabbit ears, it is limited to post 1977 bodies). 

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable dumb adapter (and such adapters are easy to find). Moreover, a large range of special adapters (helicoid adapters, tilt/shift adapters, speed boosters) for using Nikon F lenses on most mirrorless systems are available.

Using Nikon F lenses on non-Nikon SLRs and dSLRs is likewise a distinct possibility. Thanks to the relatively generous flange focal distance of the Nikon F mount (46,5 mm), adapter rings for all dSLR mounts are available as well as for a goodly portion of film-era SLR mounts. Such rings may not allow for auto aperture, but even then the lenses can be used in stop-down metering mode.

Footnotes

  1. Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
  2. Picture angle is given in degrees and concerns the diagonal picture angle. Rule of thumb:
    > 90 ° ==> Ultra-wide-angle
    70–90 ° ==> Wide-angle
    50–70 ° ==> Moderate wide-angle
    40–50 ° ==> ‘Standard’ or ‘normal’ lens
    20–40 ° ==> Short tele lens
    10-20 ° ==> Tele lens
    5-10 ° ==> Long tele lens
    < 5 ° ==> Ultra-tele lens ↩︎
  3. Length is given from the mount flange to the front of lens at infinity. ↩︎
  4. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
  5. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
  6. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎
  7. There is a further sub-class of AF-D lenses called AF-I lenses that are otherwise AF-D lenses (meaning, fully Ai-s compatible), but have an internal focus motor. Only long tele lenses were made in AF-I variants. ↩︎
  8. As of this writing, the following Nikon dSLRs fully support Aperture priority and manual metered modes on Nikkor Ai lenses: D2, D3, D4, D5, D6, D200, D300, D300s, D500, D600, D610, D700, D750, D780, D800, D800E, D810, D850, D7000, D7100, D7200 ↩︎

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