Ansel Adams, known for his large-scale black-and-white photographs of the American West, could still convey a sense of grandeur with his SX-70 at Yosemite Falls (1979). He helped found Group f/64, an association of photographers advocating "pure" photography which favored sharp focus and the use of the full tonal range of a photograph. He and Fred Archer developed a system of image-making called the Zone System, a method of achieving a desired final print through a technical understanding of how the tonal range of an image is the result of choices made in exposure, negative development, and printing.