Rosen plate folder
The Rosen has a metal body, and positive comments have been made on its build quality. There is a small focusing wheel on the photographer's right, with a lever actuating as a focus lock, and a distance scale on the left. The U-shaped front standard has an angled section. There is a brilliant finder offset to the left and a wireframe finder. The folding bed release and the leather handle are above the body. It seems that the name ROSEN is embossed in the leather of the folding bed.
Commercial life and actual examples
The only known advertisement for the Rosen plate folder is in the November 1935 issue of Asahi Camera. The camera is called simply called "Rosen" and is described as a "Hand Camera" (ハンドカメラ); it appears along with the Baby Rosen 3×4cm folder. The document mentions a choice of imported Corygon and national Rosen lenses, and gives the price range of ¥30 to ¥100. No company name is provided, but the camera was surely distributed by Ōsawa Shōkai, which was certainly the owner of the "Rosen" brand name. Most modern sources say that the camera was manufactured by Proud, certainly by analogy with the Baby Rosen, but this is unconfirmed.
The other two examples observed so far have a better front standard allowing at least vertical movements, a Compur shutter (T, B, 1–250), and a Corygon-Anastigmat 10.5cm lens, in either f/4.5 or f/3.8 aperture.
- The name appears as "Rosen" on the original box, pictured in Yazawa, p.16 of Camera Collectors' News no.235, and in an original advertisement, reproduced on p.17 of the same. The camera is called "Rosen Hand Camera" in various modern sources: Kokusan kamera no rekishi, p.343; Sugiyama, item 1240; McKeown, p.804.
- Build quality: Yazawa, p.15 of Camera Collectors' News no.235.
- Advertisement reproduced in Yazawa, p.17 of Camera Collectors' News no.235. This is the only advertisement listed in Kokusan kamera no rekishi, p.343.
- Attribution to Proud: Kokusan kamera no rekishi, p.343; Sugiyama, item 1240; McKeown, p.804; Yazawa, p.15 of Camera Collectors' News no.235.
- Sugiyama, item 1240. A smaller version of the same picture is reproduced in Kokusan kamera no rekishi, p.343.
- F/4.5: example observed in an online auction. F/3.8: example pictured in Yazawa, pp.16–7 of Camera Collectors' News no.235.
- 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 325.
- McKeown, James M. and Joan C. McKeown's Price Guide to Antique and Classic Cameras, 12th Edition, 2005-2006. USA, Centennial Photo Service, 2004. ISBN 0-931838-40-1 (hardcover). ISBN 0-931838-41-X (softcover). P.804.
- Sugiyama, Kōichi (杉山浩一); Naoi, Hiroaki (直井浩明); Bullock, John R. The Collector's Guide to Japanese Cameras. 国産カメラ図鑑 (Kokusan kamera zukan). Tokyo: Asahi Sonorama, 1985. ISBN 4-257-03187-5. Item 1240.
- Yazawa Seiichirō (矢沢征一郎). "Renzu no hanashi (145) Rōzen to Korigon" (レンズの話ローゼンとコリゴン, Lens story  Rosen and Corygon). In Camera Collectors' News no.235 (January 1997). Nishinomiya: Camera Collectors News-sha. Pp.15–9.