N°167753 · Family detail
RicohTelephoto·PENTAX K mount·1977
Ricoh XR Rikenon 135mm F/2.8
Specifications01
MountPENTAX K
Focal length135mm
Max aperturef/2.8
TypeTelephoto · Prime
Release year1977
Weight440 g
Filter size55 mm
Min focus distance1.5 m
Aperture blades8
Optical elements4
Groups4
AutofocusNo
StabilizationNo
Aperture controlAperture ring (Manual settings only)
Lens hoodBuilt-in telescopic round
EraFilm era
Production statusDiscontinued
Additional Info02
Lens TypeMedium telephoto prime lens
Summary02
Pentax K-mount telephoto prime lens with a 135mm focal length and maximum aperture of f/2.8. Intended for portraits and general telephoto use, with shallow depth of field at wider apertures.
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.