The Tiffen HT 77mm Circular Polarising Hi-Trans Double-sided Titanium Multi-coated filter has been designed with the professional photographer and imaging enthusiast in mind. These digital HT filters with hi-trans double-sided titanium multi-coating surpass even military specifications for hardness and durability.Polarizer's provide colour and contrast enhancement, protecting against reflected light which often shows up as a 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.