Nikon AI Nikkor 20mm F/4
Ultra-wide angle prime lens • Film era • Discontinued
- Announced:
- · 1977
- Production status:
- ● Discontinued
- Country of design:
- · Japan
- Original name:
- · Nikon NIKKOR 20mm 1:4
- Class:
- · Slow full-frame ultra-wide angle prime lens
- · Professional model
- System:
- · Nikon F (1959)
Abbreviations
| AI | A manual focus lens with automatic maximum aperture indexing, which is a mechanical system for coupling the lens to the camera's exposure system. Learn more |
Model history (6)
| ■Nippon Kogaku Nikkor-O 21mm F/4 • Pancake lens | M | 8 - 4 | 0.90m | ⌀52 | 1959 ● | |
| ■Nippon Kogaku / Nikon Nikkor-UD Auto 20mm F/3.5 | A | 11 - 9 | 0.30m | ⌀72 | 1967 ● | |
| ■Nikon Nikkor 20mm F/4 | A | 10 - 8 | 0.30m | ⌀52 | 1974 ● | |
| ■Nikon AI Nikkor 20mm F/4 | A | 10 - 8 | 0.30m | ⌀52 | 1977 ● | |
| ■Nikon AI Nikkor 20mm F/3.5 | A | 11 - 8 | 0.30m | ⌀52 | 1977 ● | |
| ■Nikon AI-S Nikkor 20mm F/3.5 | A | 11 - 8 | 0.30m | ⌀52 | 1981 ● | |
Specification
| Optical design: | |
| 35mm full frame | |
| 20mm | |
| F/4 | |
| 10 elements in 8 groups | |
| Nikon F [46.5mm] | |
| 94.5° (35mm full frame) | |
| On Nikon D APS-C [1.53x] cameras: | |
35mm equivalent focal length: | 30.6mm (in terms of field of view) |
35mm equivalent speed: | F/6.1 (in terms of depth of field) |
Diagonal angle of view: | 70.5° |
| Diaphragm mechanism: | |
Diaphragm type: | Automatic |
Aperture control: | Aperture ring (Manual settings only) |
| 7 (seven) | |
| Focusing: | |
| 0.30m | |
| <No data> | |
Focusing modes: | Manual focus only |
Manual focus control: | Focusing ring |
| Physical characteristics: | |
| 210g | |
| ⌀63.5×35.5mm | |
| Accessories: | |
| Screw-type 52mm | |
| HN-14 - Screw-type round | |
| HK-3 - Clamp-on round | |
| Not compatible |
Sources of data
- Manufacturer's technical data.
- Nikon Sales Manual (July 1977).
- Nikon Sales Manual (June 1978).
Manufacturer description
The "basic" ultra-wide angle of many professional photographers, this versatile lens offers a wealth of picture-taking possibilities. Despite the wide 94° angle of view, it accepts standard Nikon 52mm filters - a remarkable achievement in a 20mm lens! The highly corrected optical system virtually eliminates coma aberration, once considered inevitable in wideangle lenses of this design.
Ideally suited to scenic, architectural, and interior photography, the 20mm lens is also employed in closeups, in conjunction with bellows and BR-2 ring, to get magnification up to 12X - the highest of all Nikon system lenses. Its exceptional depth-of-field makes it a natural choice for fast-moving subjects and candid "grab" shots where critical focusing is not always possible.
Notes
- This AI lens was designed for Nikon F3, EL2, EM, FE, FE2, FE10, FG-20, FM, FM2, FM10, FM3A, Nikkormat FT3 AI cameras and Nikon FA, FG, N2000, N6000 AI-S cameras.
- AI and AI-S lenses are backward compatible with Nikon F, F2, Nikkormat FS, FT, FT2, FTN, EL, ELW cameras.
- On Nikon digital SLR cameras, the automatic exposure metering with AI and AI-S lenses will not be available on D40, D40X, D60, D70, D70s, D80, D3000-D3500, D5000-D5600 series.
Other ultra-wide angle prime lenses in the Nikon F system
| ■Nikon F mount (17) | |||||||||
| Nikon Nikkor 13mm F/5.6 | A | 16 - 12 | 0.30m | -- | 1975 ● | ||||
| Nikon AI Nikkor 13mm F/5.6 | A | 16 - 12 | 0.30m | -- | 1977 ● | ||||
| Nikon AI-S Nikkor 13mm F/5.6 | A | 16 - 12 | 0.30m | -- | 1982 ● | ||||
| Nippon Kogaku / Nikon Nikkor-QD[·C] Auto 15mm F/5.6 | A | 14 - 12 | 0.30m | -- | 1970 ● | ||||
| Nikon Nikkor 15mm F/5.6 | A | 14 - 12 | 0.30m | -- | 1976 ● | ||||
| Nikon AI Nikkor 15mm F/5.6 | A | 14 - 12 | 0.30m | -- | 1977 ● | ||||
| Nikon AI Nikkor 15mm F/3.5 | A | 14 - 11 | 0.30m | -- | 1978 ● | ||||
| Nikon AI-S Nikkor 15mm F/3.5 | A | 14 - 11 | 0.30m | -- | 1981 ● | ||||
| Nikon Nikkor 18mm F/4 | A | 13 - 9 | 0.30m | ⌀86 | 1974 ● | ||||
| Nikon AI Nikkor 18mm F/4 | A | 13 - 9 | 0.30m | ⌀86 | 1977 ● | ||||
| Nikon AI-S Nikkor 18mm F/3.5 | A | 11 - 10 | 0.25m | ⌀72 | 1981 ● | ||||
| Nikon Nikkor 20mm F/4 | A | 10 - 8 | 0.30m | ⌀52 | 1974 ● | ||||
| Nippon Kogaku / Nikon Nikkor-UD Auto 20mm F/3.5 | A | 11 - 9 | 0.30m | ⌀72 | 1967 ● | ||||
| Nikon AI Nikkor 20mm F/3.5 | A | 11 - 8 | 0.30m | ⌀52 | 1977 ● | ||||
| Nikon AI-S Nikkor 20mm F/3.5 | A | 11 - 8 | 0.30m | ⌀52 | 1981 ● | ||||
| Nikon AI-S Nikkor 20mm F/2.8 | A | 12 - 9 | 0.25m | ⌀62 | 1984 ● | ||||
| Nippon Kogaku Nikkor-O 21mm F/4 • Pancake lens | M | 8 - 4 | 0.90m | ⌀52 | 1959 ● | ||||