BRIGHTNESS INDICATING COMPARISON DEVICE

摘要

Reference light having a first color within a predetermined spectral range is combined with a colored part of the light to be measured which has passed through a filter having a second color within a spectral range complementary to the predetermined range. When the combined light assumes a third color, the brightness of the measured light is equal to the predetermined brightness of the reference light. Reflecting grid surfaces are used for deflecting the reference light into the path of the colored part of the measured light.