The Secrette (セクレット) is a Japanese plate camera, distributed from 1923 by Sone Shunsuidō, and made by its manufacturing branch Tokyo Camera Works.
The Secrette is a detective camera shaped as a monocular and taking pictures from the side, inspired by the Ergo of Contessa-Nettel. The mirror viewfinder is disguised inside the fake eyepiece. The plate holders are attached to the flat side of the camera; the distance is set by inserting the holder in one of three positions, for far, mid-range and close pictures. The shutter is a rotating drum, also acting as a lens cover when in closed position; it has T, 1/25, 1/50 and 1/75 settings.
The Secrette exists in two versions. The Regular model has a simple meniscus lens and plain leather covering. It has the words ANACHROMATIC 50m/m inscribed around the lens and TOKYO CAMERA WORKS SECRETTE around the eyepiece. The Special model has a Testar 50/4.5 lens and lizard covering. The Testar lens was specially made by a French company in Paris for Sone Shunsuidō. The lens rim reads T.C.W. PARIS TESTAR and there is a serial number. The Special also has an additional lever at the top, whose purpose is unknown.
Advertisements in Ars Camera dated April and May 1924 boast the Testar Anastigmat f/4.5 lens and lizard covering and say that the camera was delivered with six single-sided metal plate holders; they do not mention the Regular model. The April advertisement mentions No.0 size and gives no price. The May advertisement mentions atom size and gives the price of ¥85. It shows the same illustrations as the previous month and also presents the camera as the "New Argus" (新アーガス); the name New Argus was also used by Saneidō for another detective camera patterned after the original Argus or Ergo.
Various surviving examples are known, but mistakes are sometimes made in reporting the exposure format.
One example of the Special model, belonging to Mr Morihara, is pictured in Sugiyama and perhaps in other sources as well; it is sometimes reported as atom size and sometimes as No.0 size. The example pictured in Morishita is maybe the same, and reportedly has atom size. The JCII museum reportedly owns one example of the Special in No.0 size and one in atom size.
One example of the Regular model, belonging to Mr Kikuoka, reportedly has No.0 size. The example pictured in Morishita is maybe the same, and reportedly has No.0 size. Another example belongs to the Pentax Gallery and reportedly has atom size.
From the documents observed so far, it seems quite clear that the Special model was first released in No.0 size, and switched to atom size at some time. No definitive conclusion can be drawn for the Regular model. It certainly exists in No.0 size; it might have switched to atom size some time after the Special model, but this is not confirmed by any advertisement, and the reports of an atom size Regular model might be mistaken. (No.0 size usually corresponds to inexpensive cameras, such as the Adam or Sweet, whereas atom size is used on more serious cameras.)
- Distance setting: Morishita, p.68 of Kurashikku Kamera Senka no.22, and picture in Yazawa, p.13 of Camera Collectors' News no.264.
- Rotating drum: Morishita, pp.68–9 of Kurashikku Kamera Senka no.22, showing a picture of a dismantled camera. Shutter speeds: advertisements in Ars Camera April and May 1924, reproduced in Yazawa, p.18 of Camera Collectors' News no.98, p.13 of Camera Collectors' News no.171 and pp.15–6 of Camera Collectors' News no.264.
- Picture in Yazawa, p.14 of Camera Collectors' News no.264.
- No.0 format is reiban (零番, No.0) or Sweet size, half of the meishi size. It is usually translated as 4×5cm, but the actual size is closer to 4×5.5cm.
- Advertisements in Ars Camera April and May 1924, reproduced in Yazawa, p.18 of Camera Collectors' News no.98, p.13 of Camera Collectors' News no.171 and pp.15–6 of Camera Collectors' News no.264.
- Advertisement reproduced in Morishita, p.70 of Kurashikku Kamera Senka no.22.
- Example pictured as No.0 size in Sugiyama, item 4011, mentioned as atom size in Yazawa, p.13 of Camera Collectors' News no.264 and perhaps pictured in the same article.
- Morishita, p.68 of Kurashikku Kamera Senka no.22.
- Example in No.0 size and in atom size respectively pictured here and here in the Center of the History of Japanese Industrial Technology.
- Example mentioned in Yazawa, p.13 of Camera Collectors' News no.264, and perhaps pictured in the same article.
- Morishita, p.68 of Kurashikku Kamera Senka no.22.
- Example pictured in Sugiyama, item 4012, and mentioned in Yazawa, p.13 of Camera Collectors' News no.264. However there is a contradiction between these two sources about item 4011, casting doubts on this report too.
- 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.28.
- Morishita Hajime (森下肇). "Atomu-han kamera no subete" (アトム判カメラのすべて, All of Atom-size cameras). 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.22, September 1992. No ISBN number. Airesu no subete (アイレスのすべて, special issue on Aires). Pp.55–70.
- 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. Items 4011–2.
- Yazawa Seiichirō (矢沢征一郎). "Renzu no hanashi (17) Chinpin renzu Tesutā" (レンズの話珍品レンズ・テスター, Lens story  A rare lens: the Testar). In Camera Collectors' News no.98 (August 1985). Nishinomiya: Camera Collectors News-sha. Pp.17–9.
- Yazawa Seiichirō (矢沢征一郎). "Renzu no hanashi (88) Modelā" (レンズの話モデラー, Lens story  The Modelar). In Camera Collectors' News no.171 (September 1991). Nishinomiya: Camera Collectors News-sha. Pp.11–3.
- Yazawa Seiichirō (矢沢征一郎). "Renzu no hanashi (174) Tesutā" (レンズの話珍品レンズ・テスター, Lens story  The Testar). In Camera Collectors' News no.264 (June 1999). Nishinomiya: Camera Collectors News-sha. Pp.11–6.