Data Sheet: Micro-Nikkor K 105 mm f/4

Pekka Buttler, 12/2022

Specifications

The table below summarizes the lens’ key specifications:

Brand:	Micro-Nikkor	Lens name	105 mm 1:4
Focal length(s) 1	105 mm	Angle-of-view 2	23°20
Maximum Aperture	f/4	In Production	1975–1977
Lens mount	Nikon F	Subfamily (if applicable)	K-type (Pre-Ai)
Length 3	97,1 mm	Diameter 4	74,0 mm
Filter ring diameter	52 mm	Weight	514 grams
Lens element count	5	Lens group count	3
Aperture blades (S/R/C) 5	7 S	Focus throw	310 °
Minimum focusing distance	47 cms	Maximum magnification	1:2
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Automatic	Aperture click stops 6	4-5.6-8-11-16-22-32

Further notes:
• Nikon traditionally refers to its macro lenses with the term ‘micro‘.
• This lens is Nikon’s first medium length (≈100 mm) macro lens that was not designed to be used with a bellows (and could instead be mounted straight on a camera).
• To achieve the extension needed to reach a short MFD, the lens uses a double helicoid (the lens extends on both sides of the focus ring (see pic below).
• It is not a ‘true macro’ lens in that it does not reach 1:1 maximum magnification without the dedicated PN-1 extension tube (when using that tube, the lens no longer reaches infinity).
• About 15 000 copies were made (of the K-type).
• The successor is the Ai 105 mm f/4 which is largely the same lens.
• The front lens is not deeply recessed, but the lens also offers a built-in hood.

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.

Development of the short Micro-Nikkor lens

Nikon has been producing Micro lenses since 1961 (before that the customary approach was to use lenses dedicated for use on a bellows). Nikon has further also divided its micro offering in three segments: short micro lenses (50-60 mm); medium micro lenses (105–135 mm); and long micro lenses (≈200 mm). Most early long micro lenses were branded ‘Medical’ and contained an integrated light source.

The genealogy of Nikon’s 105 mm micro lenses can be summarised as follows:
• 1970–1974 (F-type) 105 mm f/4 Micro, 5 elements in 3 groups, Bellows lens (F-type)
• 1975–1977 (K-type) 105 mm f/4 Micro, 5 elements in 2 groups, 1:2 (1:1 with PN-1 extension ring) (K-type) [this lens]
• 1977–1981 (Ai-type) 105 mm f/4 Micro, 5 elements in 3 groups, 1:2 (1:1 with PN-11 extension ring) (Ai)
• 1981–1983 (Ai-s-type) 105 mm f/4 Micro, 5 elements in 3 groups, 1:2 (1:1 with PN-11 extension ring) (Ai-s)
• 1983–2020 (Ai-s-type) 105 mm f/2.8 Micro, 10 elements in 9 groups, 1:2 (1:0.88 with PN-11 extension ring) (Ai-s)
• 1990–1993 105 mm f/2.8 Micro, 9 elements in 8 groups, 1:1 (AF-type)
• 1993–2005 105 mm f/2.8 Micro, 9 elements in 8 groups, 1:1 (AF-D-type)
• 2006–2021 105 mm f/2.8 Micro, 14 elements in 12 groups, 1:1 (AF-S-type)
• 2021–today 105 mm f2.8 Micro, 16 elements in 11 groups, 1:1 (Z-mount)

Adapting

There are good chances this lens can still be used natively:
• If the lens has been AI’d, this lens can be used natively on all current high-end Nikon dSLRs and several earlier medium-to-high-end older Nikon dSLRs ⁸ as well as all post-1977 Nikon Film cameras.
• If it is in its original Pre-Ai form, it can be used natively on the Nikon Df and on all Nikon F-mount film cameras produced before 1977. When doing macro photography on a Film SLR, remain mindful of effective aperture.

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 ↩︎