Polarizing filters are useful for outdoor digital photography. Earlier film cameras needed filters to modify the colors and generate effects as well, but these can be easily done without filters in the newer digital cameras. However, even in digital cameras, polarizing filters are required to create the effect of a polarizer.
A polarizer is a device which converts unpolarized light or light of mixed polarization to a light of single polarization. It eliminates glare from reflective surfaces and increases the overall color saturation of the photograph, bringing out rich deep colors in the photograph.
The light reflected back from the surfaces of the objects becomes polarized after reflection and a polarizing filter is used to absorb this light. Thus, the filter gives clearer results than a dark filter. Rotating the angle of the polarizing filter helps get a clearer image and eliminate unwanted light that is reflected from the surface of the objects.
Types of Polarizing Filters
There are mainly two types of polarizing filters for digital cameras, viz., linear polarizers and circular polarizers. Both work in the same manner, with only a slight difference. Circular polarizers have added optical components, which are not present in linear polarizing filters.
Linear Polarizing Filters
These are nothing but basic filters that remove the unwanted reflected light. The light which is modulated on all the other axis is eliminated, and only the light polarized to the desired axis is passed to the camera.
Circular Polarizing Filters
The digital cameras available these days have an internal light meter and an autofocus system. However, the autofocusing system in the camera creates some problems with a linear polarizer filter. Hence, a circular filter is used instead of a linear filter.
The circular polarizer has a linear polarizer as one of its component and one another lens. The second lens converts the linear polarization into circular polarization. In short, the second polarizer eliminates the effect of polarization, as the light is fully polarized when it passes from the first lens to the second one.
It is very simple to use a polarizer in a camera. All you have to do is screw on a polarizer lens attachment to your camera, and once you are done, you are ready to take photographs.