Adams helped found Group f/64, an association of photographers advocating "pure" photography that favored sharp focus and the use of the full tonal range of a photograph. With Fred Archer, he developed an exacting system of image-making called the Zone System, which described a method of achieving a desired final print through a deeply technical understanding of how tonal range is recorded and developed in exposure, negative development, and printing. The resulting clarity and depth of such images characterized his photography.
With trustee David H. McAlpin and curator Beaumont Newhall, Adams was a key advisor in establishing the photography department at the Museum of Modern Art in New York, an important landmark in securing photography's institutional legitimacy. He helped to stage that department's first photography exhibition, helped found the photography magazine ''Aperture'', and co-founded the Center for Creative Photography at the University of Arizona.