The Hoya 49mm Polariser Filter 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 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. Hoya's polarising filters do not affect the overall colour balance of a shot. Please note: this is a linear polariser and therefore not suitable for Auto Focus cameras. For these you require a circular polariser.