Bower 58mm Digital HD Circular Polarizer FilterThe Bower 58mm Digital HD Circular Polarizer Filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non metallic surface. This results in a noticeable increase in the saturation of skies and foliage, as well as clearer imagery when photographing in hazy conditions. A circular polarizer differs from a linear polarizer in that it supports full use of a camera's autofocus and auto exposure