Polarized light vibrates in only one direction. Ordinarily, light rays vibrate
in all directions at right angles to their direction of travel. When light waves
strike a series of parallel microscopic slots, all the light that passes through
vibrate in one direction. Filters that polarize light have practical use in
photography and in simulating motion on overhead projecturals. Specular
light reflected from nonmetallic surfaces at any angle between 32° and 37°,
is polarized in such a manner that the light rays vibrate in a direction parallel
to the reflecting surface. Light reflected in this manner is said to be plane
polarized and is seen as glare.
Figure 2-6 shows plane polarization or the characteristics of glare.
Figure 2-6.Plane polarization or glare.