|image by wolf4max (Image rights)|
Pentax is a Japanese camera maker, founded in 1919.
The company that would become Pentax was founded in 1919 as Asahi Kōgaku Kōgyō G.K. (旭光学工業㈾). It was originally an optical company, beginning by making glasses under the Aoco brand (presumably the acronym of Asahi Optical Company), and made its first Aoco projection lens in 1923. It began to produce camera lenses in the early 1930s, under the impulsion of the CEO Kajiwara Kumao (梶原熊雄) and his closest collaborator Matsumoto Saburō (松本三郎). These lenses were not marked as made by Asahi, and were produced lenses for various camera models made by other makers. From 1933, the company produced Optor and meniscus achromat lenses designed at Rokuoh-sha for Konishiroku models. From the mid-1930s to the end of World War II, the company was also the main supplier of Molta, then Chiyoda Kōgaku Seikō (predecessors of Minolta), whose cameras were equipped with Coronar and Promar lenses.
The company changed status in 1938, becoming Asahi Kōgaku Kōgyō K.K. (旭光学工業㈱) or Asahi Optical Co. based in Tokyo.
The first camera produced by Asahi was the Asahiflex, that was also the first Japanese 35mm SLR, made as a prototype in 1951 and released in 1952. One of the models of the Asahiflex series, the Asahiflex IIb, was the first 35mm SLR to have an instant-return mirror, thus solving the problem of mirror blackout which had plagued SLRs up to that time (early SLRs left the mirror in its "up" position until the camera was wound for the next shot, blacking out the viewfinder).
| SLRs Pentax 67 and Pentax MX|
image by Colton Allen (Image rights)
Pentax was originally the name of another 35mm SLR camera model, introduced in 1957 and successor of the Asahiflex. The name is derived from the shape of the prism used in SLR cameras (pentaprism), and the ending deliberately looks like the Zeiss Ikon Contax. In fact, the name Pentax was a property of Zeiss Ikon (West) until they sold it to Asahi Optical Co., maybe strategically because ZI's East-German concurrent had relabeled its Contax S SLRs to Pentacon.
Many Pentax cameras were sold stamped with the name "Honeywell". Actually Honeywell was only a distributor, and these cameras were exactly the same as the ones stamped with the Asahi name. But more and more Pentax became a big brand, especially for SLR. Thus after a while the company offered not just 35mm SLRs but also complete camera systems around its Pentax 67 SLR for rollfilm and its tiny and popular Pentax Auto 110 for type 110 film cassettes. And in 1975 Pentax tried to take the lead with a new lens bayonet with same flange/film distance as the M42 screw mount, thus making it easier for lens makers to offer lenses for both mounts. In fact it should be an open bayonet standard, and really, a handful of other renowned camera makers used the Pentax's K-mount too: Zenit, Topcon, Chinon, Cosina,Ricoh, Samsung. But most important: The mount was further developed and still in use for Pentax's digital SLRs and even for one of its CSCs.
The company kept the name Asahi Optical Co. until it became Pentax Corporation (ペンタックス㈱) in 2002. After successful prototyping since 2000 the company launched its first DSLR in 2003, with Pentax K mount. A merger with the Hoya Corporation was completed on October 1, 2007. The new name is Hoya Pentax HD Corporation (HOYAペンタックスHD㈱). In summer 2011 Hoya announced that it will sell the imaging branch of Pentax to Ricoh while it will keep the medical branch of Pentax for itself.
| Pentax' smallest SLR|
image by Vagn Sloth-Madsen (Image rights)
In July, 2011 Ricoh announced its intentions to purchase the Pentax photographic-equipment business from Hoya (who, however, will retain some Pentax-branded medical product lines, etc). In August of 2013, the name of the company has been changed to Ricoh Imaging. The Ricoh branding are to be used on compact cameras while Pentax branded products will be on DSLR, interchangeable lens compact cameras and binoculars.
- Pentax MZ-D (2000) prototype, never released
- Pentax *ist D (2003)
- Pentax *ist DS (2004)
- Pentax *ist DL (2005) also sold by Samsung as GX-1L
- Pentax *ist DS2 (2005) also sold by Samsung as GX-1S
- Pentax *ist DL2 (2006)
- Pentax K100D (2006)
- Pentax K110D (2006)
- Pentax K10D (2006) also sold by Samsung as Samsung GX-10
- Pentax AP 50th Anniv (2007) concept, never released 
image by Φ 錯覺Ψ (Image rights)
- Pentax K100D Super (2007)
- Pentax K20D (2008) also sold by Samsung as Samsung GX-20
- Pentax K200D (2008)
- Pentax K-m (2008) also sold as Pentax K2000D in North America
- Pentax K-7 (2009)
- Pentax K-x (2009)
- Pentax K-5 (2010)
- Pentax K-r (2010)
Medium Format SLR
- Pentax Q (2011)
Point and Shoot Cameras
K-mount autofocus SLR
- Pentax SFX (SF1) (1987)
- Pentax SF7/SF10 (1988)
- Pentax SFXn/SF1n (1989)
- Pentax Z-1/PZ-1 (1991)
- Pentax Z-10/PZ-10 (1991)
- Pentax Z-20/PZ-20 (1993)
- Pentax Z-50p (1993)
- Pentax Z-5 (1994)
- Pentax Z-5p (1995)
- Pentax Z-1p/PZ-1p (1995)
- Pentax Z-70/PZ-70 (1995)
- Pentax MZ-5/ZX-5 (1996)
- Pentax MZ-10/ZX-10 (1996)
- Pentax MZ-3 (1997)
- Pentax MZ-5n/ZX-5n (1997)
- Pentax MZ-50/ZX-50 (1997)
- Pentax MZ-7/ZX-7 (1999)
- Pentax MZ-30/ZX-30 (2000)
- Pentax MZ-S (2001)
- Pentax MZ-6/ZX-L (2001)
- Pentax MZ-60/ZX-60 (2002)
- Pentax *ist (2003)
K-mount manual focus SLR
Pentax K series:
Pentax M series:
- Pentax MX
- Pentax ME
- Pentax ME Super
- Pentax ME-F
- Pentax MV
- Pentax MV1
- Pentax MG
- Pentax MF
- Pentax MF-1, scientific use
Pentax A series:
Pentax P series:
Screw-mount Pentax SLR
- Pentax AP
- Pentax K
- Pentax S
- Pentax S1 / H1
- Pentax S1a / H1a
- Pentax S2 / H2
- Pentax S3 / H3
- Pentax SV / H3v
- Pentax Spotmatic
- Pentax SL
- Pentax Spotmatic II
- Pentax SP500
- Pentax SP1000
- Pentax Spotmatic F
- Pentax Electro Spotmatic
- Pentax ES
- Pentax ES II
- Pentax Espio IQZoom series (e.g. Espio, Espio 928, Espio 115, Mini, IQZoom 135M Date, Zoom60-X, Zoom95-WR)
- Pentax PC series (e.g. PC-33, PC35 AF-M, PC-300 Date, PC-606W)
- Pentax Mini Sport 35AF (35mm, f/3.8)
- Pentax Pino series (e.g. Pino 35M)
- Pentax Sport (DX)
645 Medium Format
6×7 Medium Format
1979-1983 interchangeable lens SLR
Pentax have produced many different types of lens for the K-mount. They are summarized in the table below.
|Type||Focus||Focal Lengths Produced||Zooms/Primes||Lens Coverage||Auto Aperture?||Aperture Ring?|
|K Lenses||Manual||15mm-2000mm||Primes||36x24mm (35mm film)||No||Yes|
|M Lenses||Manual||20mm-2000mm||Both||36x24mm (35mm film)||No||Yes|
|A Lenses||Manual||15mm-1200mm||Both||36x24mm (35mm film)||Yes||Yes|
|F Lenses||Screw-drive Autofocus||17mm-600mm||Both||36x24mm (35mm film)||Yes||Yes|
|FA J Lenses||Screw-drive Autofocus||18mm-300mm||Zooms||36x24mm (35mm film)||Yes||No|
|FA Lenses||Screw-drive Autofocus||20mm-600mm||Both||36x24mm (35mm film)||Yes||Yes|
|D-FA Lenses||Screw-drive Autofocus||50mm, 100mm (macros)||Primes||36x24mm (35mm film)||Yes||Depends on lens|
|DA Lenses||Screw-drive / SDM Autofocus||10mm-560mm||Both||APS-C||Yes||No|
- Pentax 1/21 Spotmeter
- Pentax 3/21 Spotmeter
- Pentax Spotmeter II
- Pentax Spotmeter III
- Pentax Spotmeter V
- Pentax Digital Spotmeter
- Pentax Digital Spot V
Asahi lenses on cameras from other makers
Not all examples of the cameras listed below have Asahi lenses.
Lenses not labeled as by Asahi
- no-name meniscus achromat, on the Pearlette
- Optor, on the Idea, Ohca, Pearlette, Baby Pearl and Semi Pearl
For the predecessors of Minolta:
- Actiplan (origin unconfirmed), on the Minolta and Auto Minolta
- Coronar, on the Happy, Minolta Vest, Minolta Six, Semi Minolta (I) and II
- Promar, on the Minoltaflex (I), Minoltaflex Automat, Auto Semi Minolta and Auto Press Minolta
- Promar SII 75mm f/3.5 on the Semi Minolta P
The Heliostar lenses were perhaps assembled by Asahi (see the discussion there).
Lenses labeled as by Asahi
- ↑ Yazawa, p.12 of Camera Collectors' News no.247.
- ↑ Yazawa, p.12 of Camera Collectors' News no.247.
- ↑ The Coronar and Promar lenses are attributed to Asahi in various sources, and this attribution is confirmed by the "Kokusan shashinki no genjōchōsa" ("Inquiry into Japanese cameras"), lens items Lb5, Lb39, Lc9 and N2.
- ↑ Its address in 1943 was Tōkyō-to Itabashi-ku Itabashi-chō (東京都板橋区板橋町). Source: "Kokusan shashinki no genjōchōsa" ("Inquiry into Japanese cameras").
- ↑ Japanese version of the news release found in the Hoya official website. The name "HOYA PENTAX HD Corporation" is written in capital letters.
- ↑ Summer 2011: Hoya confirms sale rumours.
- ↑ Hoya press release (PDF) on sale of Pentax assets to Ricoh
- ↑ Pentax Classic DSLR concept at Watch Impress
- "Kokusan shashinki no genjōchōsa" (国産写真機ノ現状調査, Inquiry into Japanese cameras), listing Japanese camera production as of April 1943. Reproduced in Supuringu kamera de ikou: Zen 69 kishu no shōkai to tsukaikata (スプリングカメラでいこう: 全69機種の紹介と使い方, Let's try spring cameras: Presentation and use of 69 machines). Tokyo: Shashinkogyo Syuppan-sha, 2004. ISBN 4-87956-072-3. Pp.180–7.
- Yazawa Seiichirō (矢沢征一郎). "Renzu no hanashi (157) Happī" (レンズの話ハッピー, Lens story  The Happy). In Camera Collectors' News no.247 (January 1998). Nishinomiya: Camera Collectors News-sha. Pp.11–4. (On the beginning of the company.)
- Pentax Imaging Company Official website (including the lens product list)
- Pentax Subsidiaries - Links to all official Pentax regional websites
- Official Pentax documentation. Download manuals for cameras and lenses
User groups and community websites
- Asahi Optical Historical Club - International community of Pentax enthusiasts
- Pentax Day - annual gathering of Pentax enthusiasts
- Pentax Discussion Mailing List - view the list archive online or subscribe to the list
- Pentax User Magazine - UK-based magazine website, includes Pentax discussion forum and articles
- AntiqueCameras.org Pentax 6x7 Lens Guide - comprehensive list plus eBay listings and lens test reports
- Robertstech Pentax Resources - Lens/camera compatibility, lens filter sizes and service manuals
- Boz's K-Mount Page - technical data about Pentax K-Mount gear
- Stan Halpin's Pentax Lens Page
- Pentax 67 Lens Info
- Frank Mechelhoff's Pentax Page
- Tsuga_Non Pentax pages
- Pentax pages at whitemetal.com
- Listing of most Pentax film camera manuals in English PDF format and a few HTML versions that can be translated.
- Pentax Point and Shoot film camera instruction manuals
- Pentax Flashes and Light Meter instruction manuals at Orphancameras.com
- Asahi page at Collection G. Even's site
- Asahi/Pentax Cameras Price Guide ~ Compiled prices from recent completed auctions.
- Asahi Pentax Spotmatic at Classic Cameras by RaúlM.
In French/ English :
- Pentaxiste French site
- Cameras and user manuals at www.collection-appareils.fr
- Database of Pentax-K compatible and M42 lenses at PhotoPentax.com
In Spanish :
- Historia de Pentax Digital at www.pentaxeros.com