Kajiro Kōgaku

Kajiro Kōgaku Kenkyūjo (上代光学研究所, Kajiro Optical Laboratory) is a Japanese optical company that was founded in 1939 by Kajiro Hitoshi (上代斉), who was previously an employee of Miyoshi Kōgaku. The initials K.O.L. (for Kajiro Optical Laboratory) were adopted as the brand name of the lenses. K.O.L. is engraved in the lenses in handwritten style.

The company became Gojō Kōki Seisakusho (五城光機製作所) in 1941, but at the end of the same year, the lens activity and K.O.L. name were transfered to Kokusaku Seikō, a camera maker which was already buying lenses for its Auto Keef model.

After the war, the company was revived as Sun Kōki.

Lenses

It is said that the first lens, mounted on the Mamiya Six in 1940, was the K.O.L. Trio, soon followed by the K.O.L. Special. Both are three element lenses. However the Semi Kreis, a 4.5×6 folder, had these lenses mounted in the reverse order: the original model had the K.O.L. Special and the Semi Kreis II and III had the K.O.L. Trio.

An advertisement for the K.O.L. lenses, mentioning both Gojō and Kokusaku, lists the following lenses:

• K.O.L. Anastigmat f:4.5, 75mm;
• K.O.L. Anastigmat f:3.5, 60mm, 75mm;
• K.O.L. Sola (four elements) f:3.5, 50mm, 75mm;
• K.O.L. Goka (four elements) f:2.8, 60mm, 75mm, 80mm;
• K.O.L. Xebec (six elements) f:2, 50mm.

The K.O.L. Xebec is a collapsible lens in Leica screw mount.

Cameras equipped

• Elmoflex
• Gaica II (K.O.L. Gaica)
• Auto Keef
• Semi Kreis (K.O.L. Special and K.O.L. Trio)
• Semi Kreis II and III (K.O.L. Trio)
• Lark Six (K.O.L. Trio)
• Mamiya Six
• Nōman Flex

Bibliography

• Inoue, Mitsuo (井上光朗). "Shashin renzu no yoake. Renzu-ya Funsenki" (写真レンズの夜明け・レンズ屋奮戦記, Dawn of the photographic lens – Fierce war tales between lens shops). Classic Camera Senka (クラシックカメラ専科), no.14, Oct 1, 1989. Tokyo: Asahi Sonorama. Pp 128–132.

Links

In Japanese:

• Kōgaku Seiki's Nippon camera, a page by Akiyama Michio at the Nikon Kenkyukai Tokyo website, with information about the K.O.L. Xebec and Sun Xebec