Tiffen 86mm 85B/Polarizer Combo Filter

The Tiffen 86mm 85B/Polarizer Combo Filter is a combination of both an amber color conversion 85B and a polarizer filter.

The polarizing filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarized due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarizing filter arranges, and filters, this directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of this light. This results in a noticeable reduction of glare and reflections from non-metallic surfaces and an increase in the saturation of skies and foliage.

The 85B color conversion filter helps to slightly decrease color temperatures and provide a warming effect. The 85B converts daylight (approximately 5500K) to 3200K in order to use tungsten-balanced film outdoors.

There is a total filter factor of about 4x, requiring an increase of 2 stops for normal exposure. Tiffen filters are 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.