Light rays which are reflected by any surface become polarised and the Hoya 67mm HRT Circular Polarising+ UV filter is used to select which light rays enter your camara lens. This filter will allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc.  This filter also enable colours to become more saturated and appear clearer, 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 color balance of a shot.