HOYA FUSION ONE is a series of filters based on new HOYA optical technology. It is an update on the best-selling HOYA PRO-1D series, which has been widely used by amateur and professional photographers all over the world. The word "ONE" in the naming of this series is maintained as legacy of HOYA PRO-1D, in memory of its contribution to photographers' creativity, with the belief that this new series will serve well for many decades ahead. FUSION ONE filters have been designed to match the rigorous standards and optical capabilities of modern, high-resolution lenses. They join the HOYA filter line-up as a fusion of all the highly valued specifications: Multi-layer coating, ultra-high light-transmission, professional-grade optical glass and a low-profile filter-frame. They additionally incorporate stain resistance and a water-repellent coating. Light rays which are reflected by any surface can become polarised and polarising filters can be used to select which light rays enter your camera lens. PL-CIR (Circular Polarising) filters allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colours to become more saturated and appear clearer and with better contrast. This effect is often used to increase the contrast and saturation in blue skies and white clouds. HOYA's polarising filters do not affect the overall colour balance of a shot.