The Tiffen 5 x 5" Ultra Pol linear polarising filter helps to significantly reduce reflections and glare by filtering polarised light due to reflection from non-metallic surfaces. This results in a notable increase in saturation of skies and foliage, as well as a clearer image when shooting in hazy conditions. A linear polariser differs from a circular polariser in that it does not support the use of a camera's autofocus or automatic exposure functions; it is better suited for use with manual cameras, such as viewfinder cameras, which do not rely on internal mechanisms to determine focus or metering settings.nnThis filter is constructed from Water White glass and manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding it flat to a tolerance of 1/10,000th of an inch. It has a filter factor of 4, requiring two additional f-stops of exposure for normal results, and measures 5 x 5" / 127 x 127 mm.nnn- Compared to a standard polariser, the Ultra Pol design strives to increase the polarising effect for greater reduction of reflections and increased colour saturation.n- Arranges and filters directionally polarised light perpendicular to reflected light, allowing absorption of much of the light.n- Reduces haze in distant landscapes and provides more saturated and vivid colours.n- Strongest effect when used at 90° to the sun.n- Water White optical glass for excellent clarity.nnnSpecificationsnn