The Magna is a Japanese leaf shutter made by Seikōsha, the manufacturing branch of Hattori Tokei-ten, in the 1930s and early 1940s. It was the first camera shutter made by the company, and was released around 1933. It is in #0 size, provides 25, 50, 100, B, T speeds and was inspired by the German Vario. It sometimes has a thread and needle release device.
The list is incomplete, and not all variants are concerned.
- Lily, 6.5×9 plate folder by Konishiroku (isolated example, perhaps not original)
- New Kokka Hand, 6.5×9 plate folder by Kuribayashi
- First, 6.5×9 plate folder by Kuribayashi
- First Roll, 6×9 rollfilm folder by Kuribayashi
- First Center, 6×9 rollfilm folder by Kuribayashi
- Semi First and First Six, 4.5×6 and 6×6 folders by Kuribayashi
- Speed Pocket, 4×6.5 folder by Kuribayashi
- ↑ Date: Lewis says 1933 on p.46, and Baird says 1934 on p.15 of Kuribayashi-Petri Cameras. Shunkan o torae-tsuzukeru shattā-ten, p.9, the corresponding exhibition page and the chronology of the Seiko website say 1930, but this seems implausible.
- Baird, John R. Collectors guide to Kuribayashi-Petri Cameras. Grantsburg, WI (USA): Centennial Photo Service, 1991. ISBN 0-931838-16-9. P.15.
- Kamera no mekanizumu sono I: "Hai! Chīzu" Shunkan o torae-tsuzukeru shattā-ten (カメラのメカニズム・そのⅠ・「ハイ！チーズ」瞬間をとらえ続けるシャッター展, Camera mechanism, part 1 "Cheese!" Exhibition of instant taking shutters). Tokyo: JCII Camera Museum, 2002. (Exhibition catalogue, no ISBN number)
- 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.46.
- Chronology of the current Seiko website