A digital single-lens reflex camera
(also called a digital SLR or DSLR) is a digital
camera combining the optics and the mechanisms of a single-lens reflex camera with a digital
imaging sensor, as opposed to photographic
film. The reflex design scheme is the primary difference between a
DSLR and other digital cameras. In the reflex design, light travels through the
lens, then to a mirror that alternates to send the image to either the viewfinder
or the image sensor. The alternative would be to have a viewfinder with its own
lens, hence the term "single lens" for this design. By using only one
lens, the viewfinder
presents an image that will not perceptibly differ from what is captured by the
camera's
sensor.
Ansel Adams:(February 20, 1902 – April 22, 1984) was an American photographer and environmentalist. His black-and-white landscape photographs of the American West, especially Yosemite National Park, have been widely reproduced on calendars, posters, and in books.
With Fred Archer, Adams developed the Zone System as a way to determine proper exposure and adjust the contrast of the final print. The resulting clarity and depth characterized his photographs. Adams primarily used large-format cameras because their high resolution helped ensure sharpness in his images.
Adams founded the Group f/64 along with fellow photographers Willard Van Dyke and Edward Weston.
