3492967 Equivalents, 1927 (gelatin silver print) by Stieglitz, Alfred (1864-1946); Metropolitan Museum of Art, New York, USA; (add.info.: Songs of the Sky and later Equivalents: In these disorienting and nearly abstract images, Stieglitz sought to arouse in the viewer the emotional equivalent of his own state of mind at the time he took the picture.); American, out of copyright.