Abstract

In optical-sectioning microscopy, the blur ring from out-of-focus object structures is generally assumed to be space invariant. In fact, the slight change in magnification produced by defocus and the finite Fresnel number of the microscope cause the blurring to be slightly space-variant and asymmetric about the in-focus plane. We present an accurate model that accounts for the space variance and asymmetry. The model is simple and describes the blurring from each out-of-focus object plane by a scaling operation followed by a convolution.

© 1990 Optical Society of America