N°426797 · Family detail
PentaxZoom·PENTAX K mount·1979
Smc Pentax-M 40-80mm F/2.8-4
Specifications01
MountPENTAX K
Focal length40-80mm
Max aperturef/2.8
TypeZoom
Release year1979
Weight395 g
Filter size49 mm
Min focus distance1.2 m
Aperture blades7
Optical elements7
Groups7
Min aperturef/4
AutofocusNo
StabilizationNo
Aperture controlAperture ring (Manual settings only)
Lens hoodRH-R49 - Screw-type round
EraFilm era
Production statusDiscontinued
Additional Info02
Lens TypeStandard zoom lens
Summary02
Pentax K-mount zoom lens with a 40-80mm range and max apertures from f/2.8 to f/4, intended for general-purpose to portrait use. Uses a variable maximum aperture across the zoom range.
AI-assisted summary — verify against linked sourcesWhere can this lens be adapted?
The Pentax K mount has a flange distance of 45.46 mm. A plain adapter fits a camera whose flange distance is at least 1.46 mm shorter. How lens adapters work
- Pentax DA and FA J lenses have no aperture ring. Use an adapter with its own aperture control.
- Pentax DA lenses are made for APS-C.
- Sony EAdapter · 27.46 mm
- Canon RFAdapter · 25.46 mm
- Nikon ZAdapter · 29.46 mm
- Fujifilm XAdapter · 27.76 mm
- L-MountAdapter · 25.46 mm
- Micro Four ThirdsAdapter · 26.21 mm
- Fujifilm G (GFX)Adapter · 18.76 mm
- Canon EF-MAdapter · 27.46 mm
- Canon EFAdapter · 1.46 mm
A rear element that sticks out can hit the camera mirror.
No plain adapter reaches infinity focus on: Nikon F.

Other Mounts03
No alternate mounts are indexed for this family yet.