Tilted plane photography is a method of employing focus as a descriptive, narrative or symbolic artistic device.
It is distinct from the more simple uses of selective focus which highlight or emphasise a single point in an image, create an atmospheric bokeh, or miniaturise an obliquely-viewed landscape.
Wide-angle lenses distinguish differences in depth only up to a short distance, beyond which all is in focus.
Compound lenses are built to correct this "spherical aberration" or "curvature of field".
One means of achieving this is to tilt the lens and/or the sensor or film plane in relation to each other.
This technique is based on the principle of Scheimpflug which, traditionally, is combined with small aperture to increase the gamut of focus beyond that achievable by depth of field alone.
Example of tilted plane focus: here used for emphasis and metaphor, a 135mm lens at full aperture (f3.5) with extreme tilt and swing permits focus on specific details such as the foreground sack and slaughtered dingoes through to a section of the tennis-court mesh and the distant tethered goat. Shot on a 1963 Linhof Technica III 4"x 5" drop-bed field camera.
Tilt-lens photo of a model train, shot with a DSLR camera with a 1.6x
crop factor
. The lens was swung towards right, in order to keep the plane of focus along the train. The sensor plane, the lens plane and the plane along the train all intersect to the right of the camera.
"Prayer and Praise" Julia Margaret Cameron, British, Freshwater, Isle of Wight, 1865. Albumen print 11 1/16 × 8 15/16 in. Note that the camera in this instance is tilted down toward the scene from a point above the subjects' heads. It is this angle which has forced the plane of focus obliquely into the scene, and direction of the adult models by the photographer would be necessary to ensure focus where it is placed precisely on their eyes
