Purpose:Show that light reflected from copper is a desaturate orange.
Description:Light from a slide projector reflected off a polished piece of copper plate onto a screen exhibits its classic color, as seen at the bottom of the photo above. The color at the top is a desaturated orange produced as follows: red and green filters are mixed to produce a saturated orange, then dim white light is added by a third projector to desaturate the orange color. Lamentably, in the photograph the white light from the lower projector of the three used in the color mixing, appears off-white; the real demonstration is very clear. The photograph at the right shows the experimental setup.