An exact geometrical-optics theory of holography is worked out. A simple derivation of the holographic ray-tracing equations is given; it is used to determine the principal points of a hologram. The well-known paraxial conjugate equations of holography are shown to be exact relations, if the distance and the angles are measured in an appropriate manner. The intersection of all the principal rays determine the position of the aberration-free image.
H. H. Arsenault, "Geometrical optics of holograms," J. Opt. Soc. Am. 65, 903-908 (1975)