The Tiffen 77mm Circular Polarizer Filter provides color and contrast enhancement. Reflected light often shows up as whitish glare that washes out color in an image. A Polarizer corrects this problem producing deep, dramatically blue skies. It also removes glare from non-metallic surfaces, such as windows and water. Color saturation in general, especially outdoors, can be improved significantly. It is used on cameras with beam splitting metering systems commonly found on auto focus SLR's.