The Ricoreo 16 is a prototype camera made by Riken around 1957, taking stereo pairs on 16mm film.
The prototype was made during the development of the Golden Steky or Ricoh 16, released in 1957. It was designed by Fujimoto Sakae (藤本栄), Riken's main designer in the early postwar period, who was much interested in stereo photography and had previously built another prototype stereo camera taking 35mm film. It received the name "Ricoreo", clearly forged from Ricoh and Stereo. It is said that the camera was not produced because the demand was weak.
The Ricoreo 16 was made by assembling two 16mm cameras together. It takes two strips of 16mm film, in two separate compartments. The film strips are loaded in specific double cassettes, different from the single cassettes of the Steky or Ricoh 16. The two halves of the bottom plate are removable separately, to load each film compartment independently. Each is locked by a round knob with O and C indications, containing a film reminder graduated in ASA from 10 to 200. The tripod thread is in the middle, on a fixed triangular part between the two film doors.
The rest of the camera is more conventional. The viewfinder is contained in the middle of the top housing. There is a small hump above, with the accessory shoe offset to the left and the name Ricoreo 16 engraved. The film is advanced and the shutter is wound by a lever at the left end. The shutter release is at its usual location on the right. There are two exposure counters, on each side of the viewfinder, one for each film compartment. Finally, there is a selector at the right end, with L, STEREO and R positions, to switch between single exposures and stereo pairs. It presumably engages or disconnects the film advance and shutter release on the corresponding side.
The lenses are interchangeable with the Steky and Ricoh 16 mount. Those fitting the prototype are Ricomat 25mm f/3.5, with an aperture ring and no focusing ability, engraved RICOMAT f=25mm 1:3.5 with no serial number. They were certainly built specially for the camera. The speed knob is placed between the two lenses, and has B, 25, 50, 100 positions. The shutter is synchronized via a PC socket placed next to the right-hand lens.
- Orima, p.46 of Kurashikku Kamera Senka no.27.
- Orima and Akiyama, p.79 of Kurashikku Kamera Senka no.14.
- Orima, p.47 of Kurashikku Kamera Senka no.27.
- Orima, p.46 of Kurashikku Kamera Senka no.27, says that the two lenses are focused independently, but the pictures show no focus ring, and this is surely a mistake.
- Orima Isamu (織間勇). "Rikō de tsukurareta 2-dai no sutereo-kamera 35mm-han to 16mm-han yō magajin shiyō no shisakuki" (リコーで作られた2台のステレオカメラ35mm判と16mm専用マガジン使用の試作機, Two stereo cameras made by Ricoh: a 35mm prototype and a 16mm prototype using special magazines). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.27, December 1993. No ISBN number. Stereo World (ステレオワールド). Pp.46–7.
- Orima Isamu (織間勇) and Akiyama Hideaki (秋山日出明). "Shisaku nomi de yo ni denakatta Rikō no kamera-tachi" (試作のみで世に出なかったリコーのカメラたち, Experimental-only Ricoh cameras, which were never released). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.14, October 1989. No ISBN number. Rikō kamera no subete (リコーカメラのすべて, special issue on Ricoh). Pp.79–81.