Polarization filter
Filter (glass plate or foil) from which almost completely linearly polarized light emerges.
Polarization filters can be used to avoid reflections. This is usually a rotatable lens filter that suppresses light reflections and ensures a richer color rendition. Disturbing reflections from glass panes, liquid surfaces, shiny metallic materials or smooth, reflective plastic surfaces can thus be reduced.
Two polarization filters are required to suppress unwanted reflections. The first one in front of the light source ensures that the oscillations are limited to one plane. A second one in front of the lens only lets through light of this vibration level. Other vibration levels are suppressed.
Typically, ordinary polarizing films are active between 400 and approx. 780 nm. They can therefore not be used for IR lighting.
