Colour 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 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.
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.