PURPOSE: Demonstrate complementary color shadows.
DESCRIPTION: A double bright point source is used with colored filter in one side and the other side with no filter, so the light on a nearby screen appears either off-white or slightly colored. When an object is held in the light path two shad ows are created. The shadow of the white light is the color of the second slide. The color of the shadow of the colored slide is not white, but, rather, the complementary color to the colored slide. For example, a red slide makes a cyan shadow, a green slide makes a magenta shadow, and a blue slide makes a yellow shadow. This demonstration is like Demonstration O3-01: COLOR PERCEPTION IN SHADOWS - SLIDE PROJECTORS, except that it is a little easier to move but not as adjustable.
This experimental observation forms the basis for what is known as the opponent processing theory of color vision, which is presently accepted by most scientists in this area.
REFERENCES: (PIRA unknown.) See Demonstration Reference File for information on this area.
EQUIPMENT: Double bright point source with red, green, blue, and yellow plastic filters..
SETUP TIME: None.
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