ABSTRACT
Depth of field is the range of object distances over which objects appear acceptably sharp in a photographic image when viewed at the normal viewing distance. The unsymmetrical depth-of-field patterns produced when the swing and tilt adjustments are used to alter the angle of the plane of sharp focus can be useful in many picture-taking situations involving three-dimensional subjects. There are three basic controls over depth of field-relative aperture, object distance, and focal length. When a camera is focused on a given distance that is the only distance theoretically in sharp focus. Using the lens with a different-size film is the same as altering the cropping and the viewing distance. Viewing a print from a shorter distance than the diagonal of the print causes those parts of the image that appeared sharp at a normal viewing distance but were situated close to the near and far limits of the depth of field to now appear less sharp.
