講演情報
[O2-04]The Research Value of Classical Optical–Mechanical Planetariums in Japan with Special Reference to the Zeiss Model III
*Takeshi Inoue1, Tsuguto Kazu2, Katsuhiro Mouri3,4 (1. Akashi Municipal Planetarium (Japan), 2. Osaka City Science Museum (Japan), 3. Nagoya City Science Museum (Japan), 4. Nagoya City University (Japan))
キーワード：
Classical Optical–Mechanical Planetarium、Carl Zeiss Model III、Planetariums in Japan
Interest in classical optical–mechanical planetariums has been growing worldwide in conjunction with the centennial of the planetarium. The optical planetarium was developed by Carl Zeiss, and the Zeiss Model I was test-demonstrated in 1923. With the introduction of the Zeiss Model II in 1926, which enabled latitude adjustment, planetariums rapidly spread across the world. The Zeiss Model III was a transitional model developed in postwar West Germany through the modification of existing Model II projectors. At present, confirmed installations of the Model III are limited to six locations: Johannesburg, São Paulo, Baton Rouge, Nuremberg, Chicago, and Pittsburgh. The Model III incorporated several new elements later inherited by the Model IV, including refinements in the bright-star projection mechanism. However, detailed historical and technical case studies of the Model III remain scarce. Although no Zeiss Model III projector exists in Japan, representative projectors from both the pre-war Carl Zeiss (Jena) tradition and the post-war East and West German Zeiss companies are preserved. A Zeiss Model II from the former Osaka Municipal Electric Science Museum is now housed at the Osaka City Science Museum; a Zeiss Model IV from the Goto Planetarium is preserved at the Shibuya Cultural Center Owada; a Zeiss Model IV in kinetic display is exhibited at the Nagoya City Science Museum; and an East German Zeiss UPP 23/3 remains in active operation at the Akashi Municipal Planetarium. These projectors constitute important comparative materials for understanding the global lineage of optical planetariums, including the Zeiss Model III. In Japan, several representative projectors from major classical optical–mechanical lineages are preserved, and in some cases—their operational status can still be verified, a situation that is internationally rare. This presentation introduces the characteristics and historical significance of the Zeiss Model III and demonstrates that the planetarium projectors and their related materials preserved in Japan provide a valuable research infrastructure for the study of planetarium history.