50 Things Photographers Need to Know About Focus

45. TILT SHIFT LENSES

ALL LENSES HAVE a plane of focus that is exactly parallel to the sensor, with the solitary exception of tilt shift lenses. With normal lenses, you can move the plane of focus forward and backward with a turn of the focus ring. Tilt shift lenses allow you to tilt that focus plane forward, backward, left, or right. The result is that the plane of focus no longer runs parallel to the film plane, allowing scenes of great depth of field to be captured in a single image. These movements, when used properly, can bring angled surfaces into sharp focus.

Tilting the depth of field has been a large-format technique practiced for ages. ...