N°106026 · Family detail
PentaxWide·PENTAX K mount·1975
Pentax SMC 20mm F/4
Specifications01
MountPENTAX K
Focal length20mm
Max aperturef/4
TypeWide · Prime
Release year1975
Weight300 g
Filter size58 mm
Physical length57 mm
Min focus distance0.25 m
Max magnification0.12
Aperture blades5
Optical elements12
Groups10
Min aperturef/22
AutofocusNo
StabilizationNo
Aperture controlAperture ring (Manual settings only)
Lens hoodPH-S58 - Clamp-on rectangular
EraFilm era
Production statusDiscontinued
Additional Info02
ModelSMC
FormatFull-Frame
SeriesK Series Prime
Squeezenone
Lens TypeUltra-wide angle prime lens
Iris Blades5
Release Date1975
Data Protocolnone
Focus Zoom Rodnone
Front Diameter Mm63
Field Notes02
20mm f/4 prime lens for Pentax K-mount cameras, suitable for wide-angle landscape and general photography. Fixed focal length with a moderate maximum aperture for everyday light levels.
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Other Mounts03
No alternate mounts are indexed for this family yet.