title: Out-of-focus images; some properties, uses, and a geometrical explanation.
abstract: Out-of-focus images tend to move and split when obstructions are passed through or near the nodal planes of the image forming lens, while in-focus images do not show such effects. Geometrical optics is used to produce a qualitative explanation of these effects with the object of utilizing them for automatic focusing and rangefinding devices. Several problems in such devices are briefly discussed and a proposed automatic rangefinder is described.
authors.affiliation: Information Management, Inc., 432Clay St., San Francisco, California 94111, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Harrison