Abstract

Some aspects are considered of the images of isolated pinholes, small openings in an otherwise opaque field, and pinspots, small opacities in an otherwise clear field. Image formation is treated using scalar diffraction theory and the Kirchhoff approximation. The power in a pinhole image varies as the square of the area of the pinhole, while the power missing from a pinspot image varies as twice the area of the spot. Pinhole and pinspot images are not complementary. Pinspot images are much more sensitive to the size of the source, even for small spots. Computer imaging simulations show the variation of pinhole and pinspot images with their size and with the source.

© 1985 Optical Society of America