It is a vertical folder with a die-cast body and a top housing placed on the right as seen by the photographer holding the camera vertically. This is the reverse of the usual arrangement but allows to have a body release actioned by the right hand's finger. The optical finder protrudes from the top housing and is slightly offset to the left. There is an accessory shoe immediately on the right. On the right end of the top plate, there is a dial that seems to be a film reminder. The advance knob is at the left end, near the folding bed release button. The Semi Oscon has automatic stop advance. The back is hinged to the right.
The folding struts are engraved with a YK logo (certainly for Yamagata Kikai), and the body seems to have a nameplate marked Oscon screwed or riveted to the front.
The camera is advertised by Ōsawa Shōkai together with the Primoflex or Topcon 35 cameras made by Tōkyō Kōgaku, in a way that ambiguously suggests that it was made by this company too, with no mention of Yamagata. (For example, in this advertisement dated 1954, reproduced in the Shashin-Bako website, we read the following: "Applaused cameras by Tōkyō Kōgaku, representing the Japanese optical world", translation of "日本の光学界を代表する東京光学の絶讃カメラ"). This is obviously intentional, as Tōkyō Kōgaku was a reputed company while Yamagata Kikai was virtually unknown.
- 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. Item 433. (See also the advertisement for items 785–6.)
- Lewis, Gordon, ed. The History of the Japanese Camera. Rochester, N.Y.: George Eastman House, International Museum of Photography & Film, 1991. ISBN 0-935398-17-1 (paper), 0-935398-16-3 (hard). P. 79.