Depth of field

In photography, the distance between the nearest point and the farthest point in the subject which is perceived as acceptably sharp along a common image plane. For most subjects it extends one third of the distance in front of and two thirds of the distance behind the point focused on.Example: Abelardo Morell (American, born Cuba, 1948-), Farewell to Arms, 2001, close-up photograph of a page of Ernest Hemingway's book placed at an angle to the camera, with the lens's aperture opened to produce a depth of field which makes the nearest and farthest portions of the page out of focus. Notice that the depth of field permits the viewer to see the paper's texture in sharp focus only in the center of the picture.Also see differential focus.