Originally designed by Zeiss for an alliance with Pentax, it was intended to be a common lens mount for a proposed series of cameras and lenses.

Both of these linkages are arranged so that they are aligned and spring-loaded by the act of inserting the lens and turning it until it locks.

The lens was somewhat large and cumbersome since it had to enclose both the focusing motor (with gears) and batteries to power it.

It allows the lens's aperture to be set by the body, and thus permits shutter priority and program auto exposure modes.

This allows the body to easily set a specific aperture, since the relationship to F stops is linear.

It adds a small drive shaft to the KA-mount, allowing the body to adjust the focus of the lens.

This makes the lenses less bulky than the earlier KF-mount, which had both a motor and batteries inside the lens.

It carries the following information: focal length, distance to the subject, exact absolute f-stop value, and lens size.

At the time of its introduction, the following Pentax DSLR bodies were compatible with the new mount: K-70, K-50, K-S2, K-S1, K-1, K-3 II, with all but the K-70 requiring a firmware update.

[3] All digital K-mount Pentax SLR bodies as well as some lower-end film cameras lack the ability to read the position of the aperture simulator.

Instead, stop-down metering must be carried out by pushing the “green button” on the camera before taking a shot.

It supports Ricoh's own implementation of shutter priority and auto exposure modes, similar to the KA-mount but much simpler.

[3] Lenses locked to the camera body this way are difficult to remove and may require complete dismantling.

Pentax designed the K-mount wide enough to allow an adapter to fit between the M42 thread and the K bayonet.

There are however other third-party adapters that add to the flange focal distance so that one loses the ability to focus to infinity.

Many old M42 lenses have a modern-day cult reputation, including the (Pentax) Asahi Takumar range.

There are some Petri adapters to K-mount but they do not allow to infinity focus due to the different flange distance.

Pentax made adapters for its medium-format lenses to use on the K-mount, both the 645 and 6×7, and for the Hasselblad Bayonet type.

The T-mount was initially developed by Tamron (1957) to allow the easy adaption of generic 35 mm SLR optics into multiple mounts.

[citation needed] These are adaptors designed by Tamron to allow the transfer of aperture setting from lens to camera or vice verse, including the Adapt-A-matic (1969), Adaptall (1973) and Adaptall-2 (1979).

Carl Zeiss of East Germany marketed a number of lenses for the K-mount through its sales network.

The "real" 35 mm East German made Carl Zeiss Jena Lenses were available at the same time but only in Praktica B-mount.

Carl Zeiss is one of the most prestigious names on the photographic world; it re-launched its line of lenses for the K-mount in 2008, mainly due to the growing popularity of both Pentax and Samsung digital SLRs.

Hannes apparently sought low cost providers and Hanimex lenses have a poor reputation among users.

Made for the Zenit cameras by KMZ Hoya, a leading manufacturer of optical glass, purchased Pentax in 2008.

Miranda was a brand name used by the Dixons group in the UK, mostly for Cosina made products.

[12] Polar is a brand of Samyang Optics, a South Korean third party lens manufacturer.

[14] This lens uses the Ricoh KR-mount version: Sakar is a commercial American company that used to sell K-mount lenses.

[19] Sears is an American commercial company that sells relabeled lenses and cameras at their own stores in the United States for a number of years.

- PLM (Pulse) Glass: AL (aspheric lens) - ED (extra low dispersion lens) Coating: smc (super multi coating) - HD (high definition coating) Sealing: WR (weather resistant) - DA* (lens is sealed) - AW (All Weather) Features: PZ (Power Zoom) - QS (Quick Shift, most DA & all D FA lenses) - RE (retractable lens barrel) - digital aperture control (with PLM lenses on KAF4)) - IF (Internal focusing) See also: Pentax K-mount lenses Mount: