This 138mm Tiffen Combination 85B/ND Filter blends both an amber color conversion 85B and a neutral density filter. The ND filtration provides a 4-stop exposure reduction for darkening the entire image in order to photograph with a wider aperture or slower shutter speed than normally required. The 85B filtration covers the entire filter plane and converts the color temperature to 3200K for use with type B (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 85B and a neutral density filter.
1.2 ND filter darkens the image, allowing you to photograph with a longer shutter speed or wider aperture than normally required.
85B filter converts the color temperature to 3200K, allowing you to use type B tungsten-balanced film in daylight situations.