As a photographer, I like to use polarizer whenever it is possible. Polarization A light wave is an electromagnetic wave which travels through the vacuum of outer space. Light waves are produced by vibrating electric charges. A light wave which is vibrating in more than one plane simultaneously is referred to as unpolarized light. Light emitted by the sun, by a lamp, or by a candle flame is unpolarized light.
Unpolarized light can undergo polarization by reflection off non-metallic surfaces.
The extent to which polarization occurs is dependent upon the angle at which the light approaches the surface and upon the material which the surface is made of. Non-metallic surfaces such as asphalt roadways, snow fields and water reflect light such that there is a large concentration of vibrations in a plane parallel to the reflecting surface. A person viewing objects by means of light reflected off of non-metallic surfaces will often perceive a glare if the extent of polarization is large. Fisherman are familiar with this glare since it prevents them from seeing fish which lie below the water. Light reflected off a lake is partially polarized in a direction parallel to the water's surface.