Ansel Easton Adams (February 20, 1902 – April 22, 1984) was an American landscape photographer and environmentalist known for his black-and-white images of the American West. 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.
Adams was a life-long advocate for environmental conservation, and his photographic practice was deeply entwined with this advocacy. At age 14, he was given his first camera during his first visit to Yosemite National Park. He developed his early photographic work as a member of the Sierra Club. He was later contracted with the United States Department of the Interior to make photographs of national parks.