Ansel Easton Adams (February 20, 1902 – April 22, 1984) was an American photographer and environmentalist highly regarded for the crispness, clarity and depth of his black & white landscape photographs of the American West, especially Yosemite National Park, that have been widely exhibited and reproduced.

In the 1930's Adams founded the photography group known as Group f/64 which espoused "pure or straight photography" over pictorialism along with fellow photographers Willard Van Dyke, Imogen Cunningham and Edward Weston. Known for his technical mastery, he developed the "zone system" of controlling and relating exposure and development and published 8 portfolios of original, photographic prints. Seen in a more traditional art history context, Adams was the last and defining figure in the romantic tradition of nineteenth-century American landscape painting and photography in the tradition of Thomas Cole, Frederic Church, Albert Bierstadt, Carlton Watkins, and Eadweard Muybridge and the direct philosophical heir of the American Transcendentalists Ralph Waldo Emerson, Henry David Thoreau, and John Muir. He grew up in a time and place where his zeitgeist was formed by the notion of manifest destiny, and that European civilization was being reinvented — much for the better — in the new nation and, particularly, in the new West. Adams died in Monterey, California.