Nikon NIKKOR 20mm f/2.8 Ai-S

Nikon NIKKOR 20mm f/2.8 Ai-S

Lens Summary

Brand: Nikon

Also Known As: Nikon 20mm f/2.8 AIS

Lens Type: Prime Lens

Format: Full Frame / FX

Focus: Manual Focus

Lens Mount: Nikon F

Release Date: 1984-09-01

MSRP Price: $674.95

Made in: Japan

Infrared Rating: Good

Production Status: In Production

Nikon NIKKOR 20mm f/2.8 Ai-S Specifications

Lens Specifications
* Supplied accessories may differ depending on country or area 
Lens TypePrime Lens
Focal Length20mm
Mount TypeNikon F
FormatFull Frame / FX
Compatible Format(s)FX, DX, FX in DX Crop Mode, 35mm Film
Compatible with TeleconvertersNo
Vibration Reduction (Image Stabilization)No
Aperture Information
Aperture RingYes
Maximim Aperturef/2.8
Minimum Aperturef/22
Maximum Angle of View (Full frame or larger format)94°
Optical Information
Lens Elements12
Lens Groups9
Diaphragm Blades7
Focus Information
FocusManual Focus
Built-in Focus MotorNo
Minimum Focus Distance0.85 ft
Filter Information
Filter Size62mm
Accepts Filter TypeScrew-on
Physical Characteristics
Weather / Dust SealingYes
Mount MaterialMetal
Dimensions(Approx.) 2.6x1.7 in. (Diameter x Length)
Weight(Approx.) 9.2 oz. (260.4g)
Other Information
Available in ColorsBlack
Supplied Accessories62mm front lens cap, rear lens cap

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Airy Magnien

Sharp in the center, but corners are not that sharp until f/8. Best used at f/5.6 and above, but the full aperture is nevertheless useful, as it facilitates manual focussing.

Conspicuous wavy distortion; correction profiles are available (e.g. in Adobe Lightroom).

Sensitive to flare. If this is a problem, better use the older 20/3.5 UD or 20/3.5 AI.

A big plus of this lens is its small size and near “nifty fifty” look. Consequently, it does not attract attention and it is possible to shoot people off axis, which is very useful under certain circumstances (street shots…).


The AI version of this lens was made between 1977 and 1981 and I’ve used it ever since. On my D850, it’s sharp in the centre of the image, less so in the corners. As I’m not interested in corners, it’s one of my favourite lenses.

Larry Miller

I’ve owned the first version of this lens for some 10+ years. Recently I got the new version with SIC on the lens elements. I like the newer version better. I’m not sure if this lens is as sharp on digital as it is on film cameras. On film, it’s very, very sharp. I like the focal length of this lens much more than using a 24mm. In my case, once you’ve used the 20mm it’s very hard to go back to the 24mm. Never was impressed with Nikon’s 24mm lenses. I do like their 28mm lenses however. The 20mm is a great lens with it’s ability to keep straight lines straight (rectilinear). Anyway, I’ve never regretted buying this focal length. Ever.