In this series Vik Muniz playfully takes on one of modernist photography's greatest heroes, Alfred Stieglitz, along with one of modernism's greatest institutions, the Museum of Modern Art. In the early 1920s Stieglitz made a pivotal series of photographs of clouds-small, abstract compositions cropped from the broad expanse of sky overhead. He called these cloud studies "Equivalents," because he saw them as pure, formal expressions of his inner emotional and psychological states. Muniz conceived his series of "Equivalents" after viewing an exhibition of Stieglitz photographs at MoMA in 1992. As he was leaving the exhibition, he noticed the cloudlike forms in the lobby's gray and white marble floor. Using hastily improvised props, including a flashlight and a dime painted white, Muniz made his own "Equivalents," which he printed at the same size and on the same paper as Stieglitz's originals. This affectionate satire cleverly sets into motion a complex series of equivalences-between a marble floor and a cloudy sky, between Stieglitz's original photographs and Muniz's reworkings of them, between the literal and the conceptual image-and thus expresses postmodernism's concern with the potency of tradition and the changes it must undergo to remain vital.