Purpose:Show colors of additive filters along with their spectra.
Description:Two sets of red, green and blue additive color filters are used to simultaneously observe the color of the filter and its spectrum. A baffle placed on an overhead projector has a cutout into which the the filter is placed to show the color of the filter. The prism spectrum setup of demonstration N1-01: PRISMATIC SPECTRUM OF WHITE LIGHT - POINT SOURCE is used with the filter placed in a holder just before the slit. The color of the light passed by the filter on the overhead projector is located on the screen adjacent to the spectrum for easy comparison.
Positive color filters are seen to pass a band of wavelengths around their apparent color, as seen in the photographs above.