Hugh P King

US Patent:

39329496, Jan 20, 1976

Filed:

Feb 20, 1974

Appl. No.:

5/444111

Inventors:

Hugh R. King - New York NY

International Classification:

G09b 2322

US Classification:

35 19B

Abstract:

A method for the visual demonstration of the formation and causes of the five Seidel aberrations and chromatism appearing on the image plane of a converging lens system. A method and device utilizing that method are provided for the refraction through a lens system of multiple pinhole images of a single object such as to visually demonstrate: (a) the respective distortions of each of said images on a movable ground-glass after they have passed through different portions of the system but prior to the system's image plane; (b) the convergence, in cinematographic-like progression on the moving ground-glass, of these multiple refracted images to and superimposition at the system's focal plane and their respective contribution to the abberrations in the composite image observed on that plane; (c) the further asymmetrical convergence or collapse of the discrete refracted images beyond the focal plane to their respective "image-apertures", said image-apertures defining the image plane of the physical pinhole apertures; (d) the visual "sommersault", as seen on the moving ground-glass, of the collapsing images whereby they appear to "squeeze" through and reverse themselves in passing through the said image-apertures; (e) the visual and readily apparent aberrations caused by the aforesaid "sommersault" when it appears near the system's image plane. A ground-glass "sandwich" comprised of two or more lightly etched glass plates is provided whereby the characteristic horizontal and vertical bright-line images of astigmatism may be simultaneously observed in the process of formation and whereby the full nature of the so-called "circle of least confusion" in optical theory may be visually shown for the first time. A changeable lens system is provided whereby the affect of the multiple bending of images in correcting projected image distortions and aberrations can be visually demonstrated in process.