sentences:  MoMA developed a world-renowned art photography collection first under Edward Steichen (1947-1961) and then under Steichen's hand-picked successor John Szarkowski (1962-1991), which included photos by Todd Webb.The department was founded by Beaumont Newhall in 1940.Under Szarkowski, it focused on a more traditionally modernist approach to the medium, one that emphasized documentary images and orthodox darkroom techniques.