The principal purpose of a polariser is to eliminate surface reflections, glare and hot spots from any light source entering the lens. It is an essential outside all purpose filter. Polariser’s create contrast between clouds and sky, and remove reflections from glass, water, foliage, and metallic surfaces. By rotating this filter, you can achieve the desired effect.
Circular Polariser’s are intended for use when cameras have internal metering systems that are susceptible to reflections. It will have the same functions as the Linear Polariser