Miyamoto Lens Kenkyūjo (宮本レンズ研究所) was a Japanese company based in Tokyo, Shinagawa in 1943. It is listed in the April 1943 government inquiry as the maker of the Cyclon 3×4cm camera and its Cyclon 50/3.5 three-element lens. The camera was distributed by Sankō-sha, the same company which sold rangefinder conversions for the Gelto and other cameras, under the same brand "Cyclon".
- "Kokusan shashinki no genjōchōsa" (国産写真機ノ現状調査, Inquiry into Japanese cameras), listing Japanese camera production as of April 1943. Reproduced in Supuringu kamera de ikou: Zen 69 kishu no shōkai to tsukaikata (スプリングカメラでいこう: 全69機種の紹介と使い方, Let's try spring cameras: Presentation and use of 69 machines). Tokyo: Shashinkogyo Syuppan-sha, 2004. ISBN 4-87956-072-3. Pp.180–7.