In the contemporary world the practical applications of the photographic medium are legion: it is an important tool in education, medicine, commerce, criminology, and the military. Its scientific applications include aerial mapping and surveying, geology, reconnaissance, meteorology, archaeology, and anthropology. New techniques such as holography, a means of creating a three-dimensional image in space, continue to expand the medium's technological and creative horizons. In astronomy the charge coupled device (CCD) can detect and register even a single photon of light.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.