Tiffen 67mm Circular Polarizer Filter (p/n 67CP). Polarizers provide colour and contrast enhancement. Reflected light often shows up as whitish glare that washes out colour 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. Colour saturation in general, especially outdoors, can be improved significantly.