Circular Polarizer - Light and sun rays that are reflected become polarized. Circular polarizing filters selectively control which polarized light rays enter your camera's lens. Circular polarizing filters reduce unwanted reflections from non-metallic surfaces like water or glass, while also enhancing color saturation and improving contrast. You can see the effect through the viewfinder or LCD screen and adjust it by rotating the filter. The filter factor changes based on how the filter is rotated and its angle relative to the sun. Circular polarizing filters do not alter the overall color balance of the shot. Includes a 1 Year Warranty.