The Hoya Circular Polarizer Filter (CPL) 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 functions.
Hoya filters feature a single coating that helps to greatly reduce surface reflections and increase light transmission. This filter is set in a low-profile, rigid aluminum filter ring that keeps the glass perfectly aligned with the lens and sensor or film surfaces.