| Pentax K mount | |
|---|---|
| Pentax K1000 without lens, showing the original K mount | |
| Type | bayonet |
| Tabs | 3 |
| Connectors | electrical pins, drive shaft for focus. |
The Pentax K mount, sometimes referred to as the "PK mount", is a lens mount standard for mounting interchangeable photographic lenses to 35 mm single-lens reflex (SLR) cameras. It was created by Pentax in 1975,[1] and has been used by all Pentax 35 mm and digital SLRs since. A number of other manufacturers have also produced many K-mount lenses and K-mount cameras.
The Pentax K mount has undergone a number of evolutions over the years as new functionality has been added. In general, the term K mount may refer to the original K mount, or to all its variations.
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. However, the plan failed to work out and the two firms parted company amicably, but Pentax retained the lens mount and at least one Zeiss lens design for its own use.
The original K mount is a simple bayonet connection with three tabs. It was introduced with the K series of cameras. The lens is locked into the camera with an approx. 70° clockwise turn (when looking at the front of the camera).
The only linkage with the camera is mechanical and involves the aperture. A slot between two of the bayonet tabs on the lens allows the stop-down coupler from the camera to sense the aperture setting on the lens and adjust the light meter display accordingly. Opposite this is the diaphragm release from the lens which extends into the camera body and holds open the spring-loaded diaphragm of the lens. When setting up a shot this keeps the diaphragm fully open. When the shutter is released, so is this lever. It allows the diaphragm to close to the desired setting while the film is being exposed, and opens it again after the shutter closes.
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.
Bodies equipped with the original K mount include the K series, the M series except the ME F, and the LX. Lenses that support it include those labelled 'SMC Pentax', 'SMC Pentax-M' and 'SMC Pentax-A'. These K mount bodies cannot use lenses that lack an aperture ring, such as FAJ or DA.
K-mount lenses can be used on all Pentax bodies, but are restricted to stopped down mode when used with "crippled" KAF mount bodies (see below).
The KF mount was Pentax's first attempt at an autofocus system. This autofocus system used sensors in the camera body and a motor in the lens. The two were connected via five new electrical contacts on the bayonet mount itself. One permitted the lens to turn on the camera's metering and focus sensors, two focused the lens (towards and away from infinity) and two appear to have been unused and may have been reserved for future functionality.
The KF mount was largely a failure. Only one camera and one lens ever used this mount, the Pentax ME F and SMC Pentax-AF 35-70/2.8. The lens was somewhat large and cumbersome [3] since it had to enclose both the focusing motor (with gears) and batteries to power it. KF and the ME-F are similar in many ways to the system used by Canon in the ill fated Canon T80, introduced several years later.
The ME F can use all Pentax K-mount lenses except for FAJ lenses, which lack an aperture ring. The 35–70 mm lens can be used on all other Pentax K-mount bodies in manual focus mode, but it must be used stopped down on "crippled" KAF bodies.
The KA mount is derived from the original K mount. It allows the lens's aperture to be set by the body, and thus permits shutter priority and program auto exposure modes. It was introduced in 1983, and is supported by A-series and P-series bodies; Pentax lenses that support it are marked 'SMC Pentax-A'. It is completely backward-compatible with the original K mount.
The aperture on the lens is set from the body by the same stop-down lever found on the original K mount, but on KA lenses this lever is proportional to the area of the aperture opening, rather than the diameter as on previous lenses. This allows the body to easily set a specific aperture, since the relationship to F stops is linear. The lenses add an 'A' setting on the aperture dial, which gives the body control of the aperture. Other, numeric settings are used for manual aperture modes—aperture priority and full manual mode.
Six electrical contacts are added to the bayonet ring. One is slightly recessed and allows the lens to indicate whether the aperture ring is set at 'A' or not. If it is, a pin on the lens extends slightly and makes contact, while if the lens is at any other setting the pin is retracted and does not make contact. The other five contacts are used to encode the lens's aperture range. Each contact on the lens is either conducting or non-conducting, providing a binary 1 or 0, respectively. Two contacts encode the lens's minimum aperture—f/16, f/22, f/32 or f/45; although no Pentax K-mount lens has ever had an f/16 minimum aperture, OEM lenses often have. The other three contacts encode the lens's maximum aperture; their meaning is dependent on the minimum aperture indicated by the lens.
The KAF mount was Pentax's second and much improved attempt at adding auto-focus to lenses. 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 also adds a seventh electrical contact, this one carrying digital information from the lens to the camera. It carries the following information: focal length, distance to the subject, exact absolute f-stop value, and lens size. This information is used to make better exposure decisions, along with the multi-segmented metering that was introduced in cameras using the KAF mount.
The "crippled" KAF mount is used on the MZ-30/ZX-30, MZ-50/ZX-50, MZ-60/ZX-60, the *ist series and the K100D/K110D. In these cameras – in aperture priority mode – the aperture is set by a dial on the camera body, and no longer on the lens. The only difference between the regular KAF mount and the crippled version is the removal of the mechanical stop-down coupler/indicator. The result is that most of these bodies can only correctly use lenses which have an "A" setting on the aperture ring or "crippled" KAF lenses. With a K/M (also known as "pre-A") lens, the body cannot tell what aperture the lens is set to with the "crippled" mount. The *ist series and K series digital cameras have a work-around which allows K/M lenses to be used in full manual exposure mode by simply pressing the AE-Lock button to stop down the lens and take a meter reading. The on-body flash only fires at full power, making it difficult with pre-A lenses (a Flash Guide Number calculation is required). This lens mount includes DA and FA-J series lenses. The MZ60/ZX60 goes 1 step further by only allowing autofocus lenses to be used. 2 lens information contacts have also been removed from this camera.
The KAF2 mount is the same as the KAF mount except that it adds two extra contacts to the inside of the mounting ring for power zooming, and transmits modulation transfer function (MTF) data through the digital seventh contact. On the K10D digital SLR model (and later models like K100D Super, K20D, Pentax K-7, Pentax K-5 and K200D) the two power contacts can also power Silent Drive Motor lenses.
The "crippled" KAF2 mount is found on Pentax DSLRs released beginning with the K10D/K100D Super. It supports the extra features of the KAF2 mount including the two power contacts for the lens. Power zoom is supported (not full support and only in K10D), as well as lenses with focus motors. Such lenses support Silent Drive Motor (SDM), allowing for quieter autofocus. Like the "crippled" KAF mount, it does not have a mechanical stop-down coupler/indicator and thus can only use stop-down metering on pre-A lenses.
The KA2 is identical to KAF, but lacks the autofocus drive shaft. Another way of looking at it is that it adds the seventh contact for digital information to the KA mount.
The R-K mount is a variation on the original K mount by Ricoh. It supports Ricoh's own implementation of shutter priority and auto exposure modes, similar to the KA mount but much simpler. The only addition to the original K mount is a small pin at the bottom which tells the body when the aperture ring has been set to the "P" setting (similar to the "A" setting on Pentax KA lenses).
The R-K mount is used on Rikenon P lenses, Ricoh bodies that include the letter 'P' in their model number, and some non-Ricoh lenses. It is compatible with all other K-mount cameras and lenses when in manual or aperture-priority exposure modes, however the extra pin needs to be removed for safe use on autofocus Pentax cameras. If this is not done, the lens may lock on the camera body and will need dismantling before it can be removed from the body of Pentax autofocus cameras. The 'P' setting is not compatible with the 'A' setting as the 'P' pin is in a different location than the 'A' contact on Pentax 'A' lenses and the flange on Pentax bodies.
Adaptors can be found to allow use of lenses with Leica M39 thread (screw) mount. If a lens originally intended for Leica Rangefinder cameras is used, focusing is limited to about 10cms. However, some SLR lenses were made in LTM 39 mount, mostly by KMZ for use in the early Zenit SLRs which had LT 39 mounts. These "Zenit" TM 39 lenses will focus properly. Or these lenses can be used in conjunction with the M42 to LTM 39 adapter.
Adaptors can be found to allow use of a non-Leica 39mm mount into the k mount, typically as a M39-M42 adapter ring that is mounted in a M42-PK adapter; they may focus to infinity.
Pentax supplies adapters to fit M42 screw-mount lenses, as do several third-party manufacturers. The M42 screw-mount system was used by Pentax prior to the introduction of the K mount. Pentax designed the K-mount wide enough to allow an adapter to fit between the M42 thread and the K bayonet. They also kept the same flange focal distance (also called registration distance or register) as the M42 screw mount, so that M42 lenses focus correctly using the correct adapter (such as Pentax original[2] or Bower). There are however other third-party adapters that add to the flange focal distance so that one loses the ability to focus to infinity. The loss of infinity-focus may not be significant in macro or close-up photography.
There is great debate in the Pentax community over the applicability and safety of adapters other than those supplied by Pentax. Many users of third-party infinity-focus adapters, such as Bowers, report difficulty in removing the adapters from camera bodies. Such adapters may require modification before they may be safely used. Official Pentax adapters, and flanged non-infinity-focus adapters, do not provoke such problems.
Many old M42 lenses have a modern-day cult reputation, including the (Pentax) Asahi Takumar range. Some manufacturers, including Carl Zeiss AG, still make lenses in the M42 mount. Only K-mount cameras have the right flange focal distance (45.46mm) to accept old M42 lenses without any optical correction or loss of infinity focus/changed close focus distance. Other SLRs with smaller flange focal distance can also accept M42 lenses with dedicated adapters: Canon EOS (44mm), Olympus 4/3rd (38.67mm), Sony (same mount as Konica-Minolta/Minolta, 44.5mm), Sigma (44mm), and other companies, but significantly not Nikon (46.5mm).
Optically corrected adapter to use Nikon AIS AI lenses on k-mount.
Adapter for Voigtlander Bessamatic Retina lenses, Voigtlander Bessamatic, Voigtlander Ultramatic, Kodak Retina SLR, or Kodak iiis lenses.
There is also some Petri adapter to K mount but those do not allow to focus to infinity due to the different flange-to-film-plane 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. Also there is a Pentacon-Six (Kiev88 CM) adapter still in production and a shift adapter to use Pentacon lenses as shift lens.
Mounts used for Telescopes, microscopes and generic optics. The T-mount was initially developed by Tamron (1957) to allow the easy adaption of generic 35mm SLR optics into multiple mounts. The T-mount is a 42mm diameter 0.75mm pitch screw mount with a 55mm flange focal distance. Later versions (T2, T4, TX) were more advanced and complex. Several other manufacturers besides Tamron have used these mounts. Because the T-mount is still used for many telescopes and microscopes, they are still available new. Note: do not confuse the T-mount (M42x0.74) and the M42 mount (M42x1.0) lenses or adapters. They are both screw mounts of the same diameter, and will mount if they are forced, but the difference in pitch can cause damage to the lens, adapter or camera mount if they are confused!
These are adaptors designed by Tamron to allow the transfer of apperture setting from lens to camera or vice verse, including the Adapt-A-matic (1969), Adaptall (1973) and Adaptall-2 (1979). When Pentax introduced the KA mount in 1983 Tamron upgraded their Adaptall-2 K mount into a Adaptall-2 KA mount. For more details see the Tamron article or the Adaptall-2 web site.[3]
PentaxManual focus
Auto focus
Almaz
Chinon
Carena
Cimko
Cosina
Edixa
Exakta
Lindenblatt
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Miranda
Porst
Promaster
Quantaray
Ricoh
Samsung[4]SearsA lot of Sears cameras were made by Ricoh and use the Pentax K mount. Some are simply rebadged Ricoh models, while others are quite different.
Topcon
Vivitar
Voigtlander
Zenit
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Angenieux is the best lens manufacturer in France, it is mainly known for its movie equipment than for photographic lenses, but it has built some of the best optics for Leica, Nikon, Canon and a few K mount lenses. Their production is limited, but their quality is among the best.
Arsat is a trade mark of Ukrainian lens manufacturer Arsenal, Kiev.
Beroflex seems to have been a German commercial firm of photographic lenses, not too much information is available yet but it looks like provided German designed lens made overseas by Japanese companies like Soligor.
Carl Zeiss Jena history can be found on the article on Wikipedia for Zeiss, here is the list of the known lenses on k mount for it. Although marketed by the Carl Zeiss Jena (East German) sales network, this lenses were made by Sigma in Japan. The "real" 35mm East German made Carl Zeiss Jena Lenses where 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 has re-launched its line of lenses for the k-mount strongly on 2008, mainly due to the growing popularity of both Pentax and Samsung digital SLR's. Carl Zeiss announced September 2010 that the ZK lenses would be discontinued fall 2010. [4]
Cima Kogaku had a patented[5] system that allowed them to build common lens bodies, and add the appropriate lens mount at the factory. The Pentax version was only K mount, not KA mount. They mostly sold their lenses on an OEM basis, with them sold under a variety of different brands. In the UK, they were sold by Photax as Super-Paragon PMC lenses. Tokyo Kogaku sold them as AM Topcor lenses for their Topcon RM300 camera. Cima Kogaku also sold them directly under the Cimko brand. (Some of the lenses below may not have ever been sold under the Cimko brand.)
Cosmicar is a division of Pentax, it commercialized video lenses, but some were released for the k mount.
CPC Lenses are also known as Phase 2 or Phase 2 CCT.
Hanimex was an Australian distributor founded by Jack Hannes after the Second World War. The name is a contraction of HANnes IMport and EXport and the company imported both European and Japanese lenses, bodies and accessories. 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.
Kalimar was an American distributor of camera equipment from 1952 to 1999 when it was acquired by Tiffen, information on lenses and manufacturers is difficult to obtain as it sell rebadged cameras and lenses from the former Soviet Union and Japan and sell it under its own name in the U.S..[6]
Kiron was a third party lens manufacturer,[7] it manufactured lenses for other mounts as well on the decade of 1980-1990
Lomo is a Russian photographic manufacturer, it made some lenses for the Almaz camera on k mount, but caution must be used as the Almaz version has some differences with the standard k mount
One of the best macro lens ever made
Luxon is a Chinese manufacturer, and there is little information available on the company or its products.
Makinon lenses were made by Makina Optical in Japan.
Petri was a Japanese camera manufacturer, which tried to capitalize on the popularity of the k mount lens base and made one camera that used the k mount with one standard lens:
Peleng is a lens manufacturer based on Belarus, it was founded on the soviet era and releases most of his lenses in then M42 mount, but it has a K mount lens:
Good sources of information on Pentax K-mount lenses: Bojidar Dimitrov's Pentax K-mount pages,[8] Stans Pentax Photography site,[9] Pentax Forum's lens reviews.[10] Bold text indicates lenses in current production/stock sale from Pentax.[11]
Polar is a brand of Samyang Optics, a South Korean third party lens manufacturer.
This lens uses the Ricoh KR mount version, Ricoh made both a XR version without the zoom pin, and the P version which has it.
This lens uses the Ricoh KR mount version:
Sakar is a commercial American company that used to sell K mount lenses.[13]
All these lenses had been marketed by Samsung and are those present on Samsung's digital SLRs[14] Schneider-Kreuznach is a traditional optics maker that do still make specialised glass and lenses (today mainly high-quality large-format lenses, enlarger lens and photographic loupes), but not for Samsung. They license their name to Samsung granted that certain minimum quality requirements are fulfilled. All the Schneider branded glass from Samsung is manufactured by Pentax and corresponds directly to Pentax lenses.[15][16]
(The mechanism uses an adapter for different mounts as part of the design, but without adapter cannot be used, similar to the Adaptall)
Sears is an American commercial company that sells relabeled lenses and cameras at their own stores in the U.S. for a number of years. As the objective was mainly commercial, quality is very different among lenses. Quality on construction in some ones is very good and in some others is plain bad. But it seems to be consistent among the same model. Some of the Sears lenses were made to fit Sears Cameras with the Ricoh K mount version and are identified as KR, but is prudent to verify it before using it on more modern cameras that may be damaged by the Ricoh pin.
Sigma is a Japanese manufacturer of cameras and lenses. It has made lenses for the k mount for a number of years. And quality among them had varied a lot. After the launch of the K10D digital SLR it launched k mount D series lenses. Such ones are designed to be used with the APS sensor size camera, but older K mount can be used as well. An increase in model numbers can be seen between 2007 and 2008 due to the success of the K10D, K100D, K100D Super, K110D, K20D and K200D cameras. Use of older Sigma lenses is possible but with caution, some Sigma older k mount lenses are with the infamous Ricoh pin.
Spiratone was a company devoted to sell photographic accessories and manage to sell some lenses under their own brand name until it closed, very few were made for the k-mount, and none of them are known to be of good quality.
Tamron is a third party vendor of photographic lenses, quality among them varies a lot. It is important to distinguish the adaptall versions from everything else, the adaptall is a generic adapter that allowed Tamron to manufacture a single lens design for a wide range of cameras, and commercialize those for specific brands with the use of the Adaptall I and Adaptall II adapters. So there is Tamron Lenses on K mount, and Tamron Adaptall I and II for K and KA mount adapters. More Information on the Adaptall can be found on the Tamron article of Wikipedia. Here the non-Adaptall versions:
Tou Five Star was the commercial brand from Toyo Optics, some lenses are labeled as Toyo Optics, Toyo Five Star or Tou Five Star, They were manufactured between 1967 and sometime around 1980 the company seems to have changed its focus to video lenses.
Vologda Optical-and-Mechanical Plant.
Zenitar is a Russian lens brand, made by KMZ. Most Zenitar lenses are also available in M42 mount. Some of these are sold as K-mount lenses but use an adapter.
![[3]](http://www.bdimitrov.de/kmp/bodies/photos/ME_F_AF35-70f2.8.jpg){kind=link}