The influence of aperture stop position on the focusing properties of a lens is investigated. Expressions are obtained for the optical coordinates in terms of the system geometry. If the aperture stop is placed in the front focal plane of the lens, the effective Fresnel number is infinite. For other positions, the effective Fresnel number can be made either positive or negative, corresponding to focal shift either toward or away from the lens and a resulting coordinate rescaling.
© 1998 Optical Society of America
C. J. R. Sheppard and P. Török, "Dependence of Fresnel number on aperture stop position," J. Opt. Soc. Am. A 15, 3016-3019 (1998)