Data Sheet: Nikkor Ai-s (new) 50 mm f/1.8

Pekka Buttler, 09/2022

Specifications

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

Brand:	Nikkor	Lens name	50 mm 1:1.8
Focal length(s) 1	50 mm	Angle-of-view 2	43 °
Maximum Aperture	f/1.8	In Production	1985–2005
Lens mount	Nikon F	Subfamily (if applicable)	Ai-s
Length 3	27,1 mm	Diameter 4	62,6 mm
Filter ring diameter	52 mm	Weight	148 grams
Lens element count	6	Lens group count	5
Aperture blades (S/R/C) 5	7 S	Focus throw	310 °
Minimum focusing distance	60 cms	Maximum magnification	1:9,6
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Automatic	Aperture click stops 6	1.8-2.8-4-5.6-8-11-16-22

Further notes:
• This lens is easy to distinguish from a plethora of other Nikon 50 mm f/1.8 lenses in that it is the only manual focus lens to have a plastic focusing ring.
• With a diameter-to-length ratio of 2,31 this lens qualifies as a pancake lens
• Should a lens hood be needed, Nikon’s dedicated offering are the HR-4 (rubber) HS-11 (steel) hoods.

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.

What camera manufacturer would not have a nifty fifty in their line-up? Interestingly, from the launch of the Nikon F system (1959) ever until the launch of the Ai 50 mm f/1.8 (1978), Nikon’s take on a nifty fifty was a 50 mm f/2 lens (for a run-down of that genealogy, see this data sheet). But with the introduction of this lens in 1978, Nikon upped its nifty fifty to f/1.8, thus gaining parity with most of the industry.

During the following decades a great many variants have been produced. To add some potential for confusion to the mix, some models were made for export markets, other for Japanese domestic markets. There was also a variants that clearly aimed for the ‘pancake’ mould. For a chronological summary of Nikon’s 50 mm f/1.8’s see below:

years	Series	optical construction	aperture blades	MFD	notes, links
1978–1982	Ai	6 elements in 5 groups	7, straight	0,45 m	[data sheet]
1979–1981	series E	6 elements in 5 groups	7, straight	0,6 m	pancake, all-black design
1980–1982	Ai-s	6 elements in 5 groups	7, straight	0,45 m	pancake, for Japanese market
1981–1985	series E	6 elements in 5 groups	7, straight	0,6 m	pancake, silver-ring design [data sheet]
1981–1985	Ai-s	6 elements in 5 groups	7, straight	0,45	for export market
1985–2005	Ai-s New	6 elements in 5 groups	7, straight	0,6	pancake, plastic focus ring [this lens]
1986–1990	AF	6 elements in 5 groups	7, straight	0,45	plastic focus ring [data sheet]
1990–2001	AF new	6 elements in 5 groups	7, straight	0,45	rubber focus ring
2002–today	AF-D	6 elements in 5 groups	7, straight	0,45	new barrel design [data sheet]
2011–today	AF-S; G	7 elements in 6 groups	7, rounded	0,45	no aperture ring
2018–today	Z	12 elements in 9 groups	9, rounded	0,4

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 ↩︎