Abstract

In a well-corrected complex lens system, with a fairly fast aperture and wide field of view, the image aberrations which limit performance are usually sagittal oblique spherical aberration and higher-order Petzval curvature. Because of aberration balancing in any well-optimized design, it may not be apparent that these two 5th-order aberrations are in fact the limiting aberrations. It is not generally recognized that it is possible to correct all the 3rd and 5th-order monochromatic aberrations to zero in relatively simple designs, without aspherics. Several years ago I found an 8-element solution and more recently several 7-element designs. Now I have found two different 6-element solutions. One has no thick lenses or strong meniscus shapes and can also be corrected for axial and lateral color with no additional elements. I suspect there may be a five-lens solution, without color correction, that would involve some thick lenses.

© 1993 Optical Society of America