Pupil filters for moderate superresolution.

Some superresolving pupils, featuring a central maximum narrower than Airy's core and a first secondary maximum of a few percent, have been computed, following Frieden's formula and his criterion of maximum superresolution for circular symmetry. A superresolution factor of about 28% may be achieved without much sacrifice of illumination. Other pupils have been investigated where the SF reaches 35%. The behavior of the sidelobes in the point impulse image is examined. The corresponding encircled energy and point impulse response are given.