PURPOSE: Demonstrate additive color mixing of lights.

DESCRIPTION: Three slide projectors in a special three-projector mount on a roll-around cart are equipped with color filters. The projectors have been re-wired so that the intensity is adjustable by changing the voltage on the bulb without affecting the fan. The colors are easily seen, and additive color mixing can be nicely shown: R+B=M, R+G=Y, B+G=C, M+G=W, Y+B=W, and C+R=W, where R=red, G=green, B=blue, M=magenta, Y=yellow, C=cyan, and W=white.

SUGGESTIONS: Use this demonstration as a way to introduce both positive (R,G,B) and negative (M,Y,C) colors.

Click here for a Color box applet, containing easy-to-use color mixing programs for Mixing Lights, Mixing Pigments, and Color Printing, created by Phillip Dukes of Brigham Young University.

REFERENCES: (PIRA 6F10.10)

EQUIPMENT: Three slide projectors with intensity controller box on rolling stand with filters.

SETUP TIME: None.