Union Kōgaku K.K. (ユニオン光学株式会社) was a Japanese company that sold the Union Semi in 1953–4 (a rebadged Zenobia) and perhaps the Union Model U at an unknown date. According to a 1953 advertisement,[1] Union Kōgaku was a microscope maker and the Union Semi was its first camera.

A company with the same name still (2007) exists and makes microscopes and other optical devices. It was founded in 1991, but it is a subsidiary of a company called Union Holdings K.K. (ユニオンホールディングス株式会社) founded in 1948.[2]

Camera list[]

Lens list[]

The Easternflex TLR was announced with Unicor[3] 75/3.5 four-element lenses made by Union Kōgaku.[4]


  1. Advertisement dated May 1953 reproduced in Kokusan kamera no rekishi, p. 202.
  2. Company profile of Union Kōgaku and company profile of Union Holdings.
  3. Name inferred from the katakana ユニコール.
  4. Kokusan kamera no rekishi, p. 346 (item 381).