Pentax K Lenses
35 interactive lens diagrams
Pentax K bayonet, introduced in 1975 | 35 mm film, APS-C digital, and full-frame digital
Pentax K replaced M42 screw mount with a bayonet while preserving a strong continuity ethos. Introduced in 1975, the mount has evolved through manual-aperture lenses, A-series electronic aperture information, autofocus KAF variants, digital APS-C DSLRs, and full-frame K-1 bodies.
The K mount is unusually adapter-friendly and backward-compatible compared with many camera systems, though features such as aperture control, autofocus drive, and electronic contacts vary by generation. Pentax's official M42 adapter also made the transition from screw mount less abrupt for photographers with existing Takumar lenses.
Its lens history includes compact Limited primes, rugged DA and D FA lenses, classic SMC coatings, and broad third-party support from the film era onward. K-mount pages are useful for comparing a long-running SLR bayonet that survived autofocus and digital without being abandoned.
Mount interface
Flange focal distance 45.46 mm, bayonet mount. 0° at 12 o'clock from the camera front; the lens-side view is the horizontal mirror. Dotted strokes mark photo-scaled or schematic (not-to-scale) dimensions.