There are several light sources, both man-made and natural that provide wide range of wavelengths that cover the while visible light spectrum, ultraviolet and infrared regions as well. For some applications of lighting such as automobile headlights and room lights, it is useful and appropriate to obtain such wavelength spectrum. Differently, it is beneficial to restrict the range of wavelengths for some tools or applications that need a chosen and limited color frequency. This will be done conveniently by utilizing filters that are specialized and reflect, dittract and refract selectively the lights that are unnecessary. This is when optical filer comes into the picture.
Basically, filters are designed into wide variety of sizes and shapes. It can also be utilized to eliminate or pass wavelengths band that ranges from hundred of nanometers to one wavelength. Filters can also be used to fine-tune the lights color temperature in order to create a light spectrum of having the feature of indoor illumination of tungsten, evening sky or even bright daylight. Moreover, filters are also iced to adjust in contrast the colored parts in white or black photography. Filters are also used to add to add and design special effects in photography. One of the best ways to observe the use of optical filter is through the use of optical dichroic mirrors.
Furthermore, there are two types of optical filters namely interference and absorption filters. Absorption filters function by decreasing the incident light through absorption of specific wavelengths. On the other hand, interference filters are used to destructively interfere and reflect with unwanted wavelengths.
Generally, optical filter is an important tool today because it helps us to use the needed light in any applications and disregard the unwanted lights. In the field of science, balance is an important aspect in light.