know light travels in a straight line and is bent
by the lens to enable the image to be focused at the film
plane. Also the effect of depth-of-field.
and front limits of the depth-of-field area in a scene are
usually determined by lines parallel to the film plane.
When the subject plane and the film plane are parallel, which
occurs when the camera is aimed directly at a wall enough
depth-of-field to render the whole scene may be obtained by
using a wide aperture.
film plane and the subject plane are not parallel to each
other, which occurs with any subject that recedes from the
camera, a smaller aperture may be used to give more depth-of-field
and include the important elements in the scene in sharp focus.
over image to view roll over image
If a view camera is used, the depth of field lines can be actually
rotated until they align themselves more closely with the subject
plane. This principle is summarized in the scheimpflug rule,
which states that a subject will be rendered with the greatest
sharpness when the imaginary lines drawn from the subject plane,
the film plane, and the lens board plane, all meet at a common
point. This happens when two or more of these planes are
rotated so that they intersect at a common point above, below,
or to the side of the camera.
a shorter exposure time can be used or the depth-of-field can