Abstract: A device for producing variable colors from projected white light and quantifying the color changes resulting therefrom is provided which is useful in color-styling designs and color shade matching. The device comprises (1) an adjustable color filter having at least two primary-color areas upon which a portion of said projected white light is incident, (2) light-attenuation means which attenuates the quantity of light transmitted from (by attenuating either the incident white light or transmitted color light) each of the primary-color areas as well as the portion of the projected light which is transmitted unfiltered, and (3) control means comprising (a) a light-measuring unit for measuring the transmitted light and generating a signal proportional to the amount of light measured, (b) means responsive to said signal to determine the quantity of each component of transmitted light present and (c) means responsive to (b) for controlling each of the light-attenuation means.

Abstract: An electron spectrometer including a high pass filter, an electron multiplier and a reflection chamber is improved by placing a planar grid in the reflection chamber between the high pass filter and the electron multiplier.