Light reflected off surfaces becomes polarised which reduces contrast when viewed through a camera. Hoya Polarising filters allow the photographer to select which light rays enter the camera removing unwanted reflections off surfaces such as water, glass, even roof tiles. Light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter your camara lens. PL (Linear Polarising) and PL-CIR (Circular Polarising) filters have the same effect, but it is important that you choose the correct version for your camera. They allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colors 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. Color and contrast enhancement Light rays which are reflected by any surface can become polarised so polarising filters are used to select which light rays enter your camera lens. CIRCULAR PL filters allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colors 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. Reduce Glare and Reflections with the CIRCULAR PL Using the CIRCULAR PL filter, reflections and glare can be reduced significantly from non-metallic surfaces. A camera angle of 30 degrees from the reflecting surface (glass, water, etc.) is ideal for maximum effect.