With circular polarizing filters, photographers can achieve creative, in-camera effects that are no longer possible after the image is taken. A polarizing filter eliminates unwanted reflections from non-metallic surfaces such as water or glass, as well as light that reflects moisture and pollutants in the atmosphere. By rotating the ultra-smooth filter, you can select just the right amount of filtration needed for the creative effect. This results in a bluer sky, greener leaves, reduced or eliminated reflections, and enhances the clarity of the final image. The Hoya Slim Circ-PL filter is multi-coated and features an ultra-thin filter frame to prevent vignetting with ultra-wide-angle lenses, which are also designed to hold a lens cap.