| 摘要 |
Design forms for wide-field mapping lenses are disclosed wherein limitations on resolving power attributable to monochromatic aberrations have been minimized, wherein chromatic aberration has been minimized over a broad wavelength band and has been reduced to zero for paraxial marginal rays at three discrete wavelengths, and wherein chromatic variations of the monochromatic aberrations (particularly chromatic variation of coma) have been substantially eliminated. Each of the lenses disclosed has an aperture diameter in the range from 10 to 15 inches, a focal length in the range from 200 to 300 inches, and a circular field of view in the range from 40 DEG to 60 DEG . Further, each lens is diffraction limited in a spectral range from 0.50 to 0.80 micron over the entire field of view. The focal surface for each lens disclosed is curved, so that illumination fall-off from the center to the edge of the focal surface varies by a factor of only about cos1.5 theta , where theta is the half-field angle of the lens.
|
