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The Tiffen 138mm Combination 85/ND 0.9 Filter blends both an amber color conversion 85 and a 0.9 neutral density filter. The ND filtration provides a 3 stop exposure reduction for darkening the entire image in order to photograph with a wider aperture or slower shutter speed than normally required. The 85 filtration covers the entire filter plane and converts the color temperature to 3400K for use with type A (tungsten) film.
This filter is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass, grinding flat to a tolerance of 1/10,000th of an inch, and then mounting to precision metal rings.
Combination of both an amber color conversion 85 and a neutral density filter.
0.9 ND filter darkens the image, allowing you to photograph with a longer shutter speed or wider aperture than normally required.
85 filter converts the color temperature to 3400K, allowing you to use type A tungsten-balanced film in daylight situations.