The Hoya Circular Polarizer Slim Frame allows you to significantly reduce reflections and glare from non-metallic surfaces. A camera angle of 30 degrees from the reflecting surface (glass, water, etc.) is ideal for maximum effect. The Circular Polariser Filter also enables 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. It also has a thin frame to reduce vignetting when using wide angle lenses, but still allows a clip-on lens cap to be used. Hoyas polarising filters do not affect the overall colour balance of a shot.