This collection consists of materials relating to Peter C. Bunnell's work as a historian and professor of photography, an author, and an active member of organizations related to photography. The bulk of the collection includes subject files, which cover photographic topics, photographers, students, lectures, photography collections, galleries or museums, and organizations related to photography. The materials in these files include press releases, exhibition announcements, and other exhibition promotional material; typewritten and handwritten notes; correspondence with photographers and colleagues from various institutions; copy prints and negatives; organizational memos, meeting minutes, and agendas; and journal articles and news clippings. A significant part of Bunnell's files throughout his career focused on Minor White, Clarence H. White, Alfred Stieglitz, and Ansel Adams, but many modern photographers are represented. Subject files from his involvement in several institutions over the course of his career include the Museum of Modern Art and the George Eastman House, among others.

The correspondence files span Bunnell's time as a student and throughout his career. Major correspondents include Ruth Bernhard, Jerry Uelsmann, Ansel Adams, Paul Strand, and Van Deren Coke.

The rest of the collection includes file groups dedicated to the Friends of Photography and the Society for Photographic Education, which include memos, meeting minutes, agendas, correspondence, newsletters, policies and procedures, and financial reports; drafts and final versions of publications that Bunnell wrote or edited, including A Photographic Vision: Pictorial Photography, 1889–1923 (1980) and Aperture Magazine Anthology: The Minor White Years, 1952–1976 (2012); and photographs from Bunnell's retirement dinner in 2002.