Cite a photo from an institution with the name of the photographer, the title of the work, the date it was taken (if known), the museum or gallery's name and the location. Use "n.d." for an unknown date on the photo. For example: Adams, Ansel. Yosemite. N.d. Musee du Louvre, Paris.
Cite a photo found in a book with the same information as the first step but add the title of the book, the book authors, publication information and page numbers. For example: Adams, Ansel. Rose and Driftwood. 1933. The Smithsonian, Washington DC. Ansel Adams Photographs. 3rd ed. By John Smith. Chicago: Photography Publishers. 238. Print.
Cite photos from electronic sources as you would cite a photo at a gallery and add the name of the website, the medium and the date you accessed the photo. For example: Adams, Ansel. Clearing Winter Storm. 1935. Stieglitz Gallery, New York. History of Ansel Adams. Web. 24 July 2011.