Koho

Koho (Kōhō) was the name of the first leaf shutter made from 1936 by Takachiho (later Olympus). All the Koho versions had a selftimer and were in #0 size. Francesch says that it was inspired by the German Prontor II. The Koho was mainly mounted on the Semi Olympus and Olympus Six, but Takachiho also sold it to other makers.

Versions and Olympus cameras equipped

The Koho shutter was originally called Laurel (ローレル, rōreru). The Laurel has 1, 2, 5, 10, 25, 50, 100, 150, B, T speeds. The pre-series version of the Semi Olympus II, with off-centered finder, was advertised in 1937 with a Laurel shutter. The name "Laurel" was dropped because it was already registered, and it is said that the transitional name "Dauled" was used.

The first version of the Koho is similar to the Laurel, with the same speed range: 1, 2, 5, 10, 25, 50, 100, 150, B, T. As seen from the front, it has the winding lever at the top right, the release lever at the top left, the selftimer lever with a red dot at the bottom left and a distance release post on the left. It was mounted on a version of the Semi Olympus I and on the series version of the Semi Olympus II.

The second version has the same controls and a top speed of 1/200. It has been observed on some Semi Olympus II.

The third version has the same speed range (1, 2, 5, 10, 25, 50, 100, 200, B, T) but it is adapted for a body release. It has the winding lever at the top left, the selftimer lever with a red dot at the bottom left, and the release also at the bottom left, activated by the cam of the body release. The aperture setting has moved to the top of the shutter housing. This version was mounted on most variants of the Olympus Six. In some advertisements for the Olympus Six the shutter was sometimes called Koho II or Koho III.

Other cameras equipped with a Koho shutter

This list is incomplete.

• first version
  • V Semi First (with a First Anastigmat 7.5cm f/3.5 lens)
  • Semi Kelly
• second version
  • a New Semi Condor. It had what looks like a complicated linkage to a body release.
• third version
  • a Mamiya Six III pictured in McKeown
  • a Zeitax with a folding optical finder and a Zeitax Anastigmat 7.5cm f:3.5 lens
  • the Sintax
• unknown version
  • Semi Proud II (Baldax copy)

On all the above cameras except perhaps the Sintax, the shutter plate is marked Olympus Tokyo N. This plate has a cut for an aperture scale placed at the bottom, and it does not fit very well with the third version of the Koho. The Sintax has a SINTAX marking at the bottom of the shutter plate, probably filling the cut.

The Kōhō name

The name Kōhō was written コーホー in katakana, but it was apparently formed from the word 高峰, which means "high peak" or "high mountain". This is a clear allusion to the Olympus name (itself from Mount Olympus).

Bibliography

• Asahi Camera (アサヒカメラ) editorial staff. Shōwa 10–40nen kōkoku ni miru kokusan kamera no rekishi (昭和10–40年広告にみる国産カメラの歴史, Japanese camera history as seen in advertisements, 1935–1965). Tokyo: Asahi Shinbunsha, 1994. ISBN 4-02-330312-7.
• Baird, John R. Collectors guide to Kuribayashi-Petri Cameras. Grantsburg, WI (USA): Centennial Photo Service, 1991. ISBN 0-931838-16-9. P. 75.
• Francesch, Dominique and Jean-Paul. Histoire de l'appareil photographique Olympus de 1936 à 1983. Paris: Dessain et Tolra, 1985. ISBN 2-249-27679-X.

Links

• Olympus history pages at the Olympus Photo Club website:
  • The Semi models
  • The Six and Chrome Six models
• Origins of the Olympus cameras in the Olympus corporate site, with links to a Semi Olympus II brochure and to an Olympus Six brochure, in pdf format