Since its early days, photography has been both a tool of and subject for scientific research. Developments in photochemistry, camera construction and lense refinement made photography an extremely successful mass medium. At the same time, photography served scientific research as a key medium for observation, documentation, education and communication. ETH-Bibliothek, the main library at ETH Zurich, is holding in its Image Archive vast collections of photographs. Among them is the complete collection of the university's own Photographic Institute, an independent service and research unit between 1886 and 1979. This new book documents both the main aspects of scientific photography, illustrating the research of many disciplines while being the subject of basic research itself. Using a rich selection of images, ranging from astronomical and micro-photography, to laboratory situations and carefully illuminated experimental installations. The introductory essay investigates the interplay between photography and the world of science, and tells the story and changing role of the Photographic Institute.