Harry Callahan was an American photographer born in Detroit. Self-taught, he began taking pictures in 1938 as a hobby and, inspired by the work of Ansel Adams, began to produce professional-quality photographs in the 1940s. His mature work is said to mingle the precision of Americans like Adams with the experimentalism of Europeans like Lázló Moholy-Nagy. His black-and-white city streetscapes and rural landscapes combine the commonplace with the starkly abstract, exploring contrasts of sunlight and shadow, tone and texture, static buildings and hurried passersby, while his many lovingly distinctive portraits of his wife and daughter are extremely personal and intimate. He sometimes used multiple exposures, and experimented with color slide film in the 1940s, again making color images from 1977 on. An influential figure in modern photography, he taught at Chicago's Institute of Design (1946-61) and the Rhode Island School of Design (1961-77).