{"id":84,"date":"2021-05-08T00:46:29","date_gmt":"2021-05-07T23:46:29","guid":{"rendered":"http:\/\/iso3200.org\/blog\/?page_id=84"},"modified":"2025-11-28T21:39:13","modified_gmt":"2025-11-28T20:39:13","slug":"pentax-k-mount-lenses","status":"publish","type":"page","link":"https:\/\/iso3200.org\/blog\/references\/pentax-k-mount-lenses\/","title":{"rendered":"Pentax K mount lenses"},"content":{"rendered":"\n

K mount was developed by Pentax and Carl Zeiss in the early 1970s and released by Pentax in 1975, after Carl Zeiss dropped out of the partnership. It is a bayonet mount with three lugs made for 35mm film format, with a focal flange distance of 45.46mm. Mount supports electric and digital communication, film and digital sensors — both APS-C and 35mm (“full-frame”). The aperture is usually controlled mechanically, with a lens clutch, but it can be controlled electromagnetically on digital cameras made after 2016. Focus can be achieved manually as well as automatically — mount supports screw-drive and digital focus control with lenses with built-in focus motors. There are contacts for power delivery used for powering in-lens motors — like motors used for Power Zoom features, focus motors and stabilization (available only in some 3rd<\/sup> party lenses). The manual focus and aperture automation variant of the mount does not need licensing.<\/p>\n\n\n\n

Jump to: K-series<\/strong><\/a>, M-series<\/a><\/strong>, A-series<\/a><\/strong>, F-series<\/a><\/strong>, FA-series<\/a><\/strong>, DA-series<\/a><\/strong>, D FA-series<\/a><\/strong> lenses; Terminology<\/a><\/strong>.<\/p>\n\n\n\n

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K-series lenses<\/h2>\n\n\n\n

Built from 1975 to 1977. K-series lenses are fully mechanical, manual focus lenses, with no aperture automation available. Aperture priority and manual modes are possible with K-series lenses.<\/p>\n\n\n\n

At this time, Pentax was testing automatic focusing systems, and released a single autofocus lens — AF Zoom 35\u2013\u200d70mm F2.8 — that worked correctly only with Pentax ME-F body. The lens had focusing motor and four AAA batteries, making it big, heavy and oddly shaped.<\/p>\n\n\n\n