Electronic imaging using a logarithmic asphere

Transmission functions are derived that are valid in the nonparaxial case f or a class of lenses that will image a continuum of points along an optical aids to a single image point. This lens, which we call a logarithmic asphe re, is then used in a digital camera. The resolution of the camera is limit ed by the pixel size of the CCD; i.e., it is not diffraction limited. Digit al processing is used to recover the image, and image-plane processing is u sed for speed. We find a tenfold increase in the depth of field over that f or the diffraction-limited case. (C) 2001 Optical Society of America.