El Mochuelo, a short-lived gallery in Santa Barbara, published the first important book on Harry Callahan as the first and only realised publication in a series of artist's monographs. In the introduction, Hugo Weber, a Swiss painter and Callahan's colleague at Moholy-Nagy's Institute of Design in Chicago writes: 'The argument as to photography being an "art or not" seemed most irrelevant to me. Harry was obviously an artist. That he chose the most common mass communication medium did not make any difference.'

First edition; 4to (324 x 280 mm, 12¾ x 11 in); black-and-white photographs printed by offset by the Meriden Gravure Company, Connecticut, texts by Hugo Weber and Harry Callahan, bibliography by Bernard Karpel, one gathering partially unopened; grey endpapers with the usual discolouring from the binder's glue, black cloth-covered boards, titles stamped in silver on spine and upper side, publisher's matching slipcase with titles in silver on upper, lightly marked and rubbed, near-fine; [240]pp.

The Book of 101 Books: Seminal Photographic Books of the Twentieth Century pp168-169; The Open Book: A history of the Photographic Book from 1878 to the present pp202-203