Digital Camera Polarizing Filter

Light is characterized by a displacement in a straight line through homogenous medium an also for it's undulating nature in all it's planes . The reflection of a ray of light on a shiny non-metallic surface can eliminate the undulation in some of it's planes (polarization); the greater or smaller polarization depends on the angle the ray of light forms with the surface. There is no polarization when the ray is reflected in a perpendicular direction to the surface and neither when the angle is too flat. Normally polarization happens in the two beams which are reflected at an angle around 30 º. For a determined angle, the polarization is maximal and the undulation is produced only on one plane.

There are also transparent mediums which polarize the light which passes through them. A polarizing filter acts like a optic crack that transmits only the light that vibrates in the plane of that crack. The intensity of the already polarized light can be regulated by turning the filter on it's axis.

The two most frequent sources of polarized light are shiny non metallic surfaces and the sky. With a polarizing filer, depending on the observation angle, we can eliminate the light reflected by the shiny surfaces, reflections . The polarizing filter lets us see through the surface of the water, glass and varnished paints, reach the color of shiny surfaces, such as leaves, skin, and give them a saturated dull appearance. (See next page.) Also, the polarizer is the only filter that lets us regulate the intensity of the light from the sky with color film. The light from a blue, clear sky is strongly polarized in the region placed at a straight angle with the sun. If we turn the polarizer while we observe that region in the sky, we can see that in a determined position, there is a considerable reduction of it's apparent brightness.