Harry Callahan taught at the New Bauhaus, later renamed Institute of Design, Chicago, from 1946 to 1961 and applied the experimental impulse of its pedagogy to his own photographic process. Turning his camera on his wife, Eleanor, he investigated a number of technically challenging approaches, including double exposures created by rewinding the film in camera. Callahan often combined tightly framed or cropped images with high contrast, reducing Eleanor’s image or figure to a study of abstract forms in light or shadow.
Additional text from Seeing Through Photographs online course, Coursera, 2016