About Authors Changes Copyright Index References To Do WWW
Bodies Flashes Lenses Miscellaneous Power Technology Teleconverters
M 28/2.8 (version 2)

General Description

This lens is extremely interesting. Its lens mount is of the "original K-mount" type, and its name associates it undoubtedly with the M-series of K-mount lenses. On the other hand, the lens shares its most important characteristics with the later SMC-A lens: the linear aperture mechanism and the updated optical formula. Even the focusing ring is of the A-style.

Guesses can be made that in 1982 Pentax was already hard at work developing the A-series bodies and lenses, and when parts for the "original" M 28/2.8 lens were depleted, it was decided to switch to production of the new lens, but without exposing the externally visible A-series features — electrical contacts on the lens mount and "A" position on the aperture ring. Still, this lens with its low production numbers is a rather unique piece of K-mount history.

Product Information
Exact Namesmc PENTAX-M 1:2.8 28mm
Years of Production1982 ~ 1984
Availabilityused, once in several years
Catalog Number22977
Sold with Hood
Sold with Casededicated hard case: exact name unknown

Technical Specifications

Optical Formula7 elements in 7 groups
Aperture Rangef/2.8 ~ f/22
Number of Aperture Blades5
Minimum Focusing Distance0.3 m
Maximum Magnification0.13 X
Filter Diameter49 mm
Maximum Diameter63 mm
Length37 mm
Weight170 g
Capplastic clip-on cap, 49 mm
Fitting Hood(s)clip-on hood: PH-S49
Fitting Case(s)dedicated hard case: exact name unknown