Perspective control lens

Perspective control lenses have special tilt and shift movements for correcting converging lines (shift movement) in architectural images, for example, and adjusting the plane of sharp focus (tilt movements) for objects at an angle to the camera. By applying a vertical shift you can bring the top of a tall building into the frame without tilting the camera (this is what caused the converging vertical effect). By applying a tilt movement to the lens you can change the plane of sharp focus away from the perpendicular towards the plane of your subject – this increases the depth of field available.

See also: Lenses explained