"It might be said that the subject of Callahan"s photographs is photography, and that his world exists essentially as a formal problem." John Szarkowski Harry Callahan was one of the most respected and influential American photographers of the modern era. He was a master of traditional genres such as portraiture, landscape, architecture and nature studies, but also experimented with new ways of using the medium. One of Callahan"s favorite themes was the repeating pattern, whether in multiple reeds reflected on a lake"s surface or the rows of windows on a building"s facade. While lesser known than some of his other work, Callahan"s collages demonstrate an intense interest in and profound understanding of the process of photographic seeing. His collages are rigorous yet playful explorations of a visual world created in his studio. The subject is either faces cut from magazines or rectangles cut from black or white paper. Callahan then photographed the collages pinned to his studio wall on his 8x10 inch view camera, one leading to the next to create this never before published series.