Recent articles in Scientific American and Fortune Magazine have described what is purported to be a new theory of color vision by Edwin Land of Polaroid fame. The basic experiment by Land is the following. A scene to be photographed is composed of different colored objects. Two positive transparencies of this scene are made; one from a black and white negative taken through a red filter (passing only the longer wavelengths such as red, orange, and yellow and called the "long record"), and the second a black and white negative taken through a green filter (passing only the short wavelengths such as green and blue and called the "short record"). When the two transparencies are projected simultaneously and superimposed (the "long record" through a red filter and the "short record" with no filter over the projector lens), the scene appears in color.
Each slide alone produces either a monotone or