Ideal for portraiture, the 77mm Digital HT 812 Warming Filter from Tiffen is used to improve skin tones when working in cool lighting conditions. This filter offers a greater warming effect than a skylight 1-A filter and is well-suited for use outdoors on overcast days or on sunny days when working in open shade. It can also be used to absorb the strong blue cast of an electronic flash for more balanced, lifelike skin tones.
The filter is constructed using Tiffen's ColorCore technology, which involves lamenting the filter material between two pieces of water white optical glass, grounding flat to a tolerance of 1/10,000th of an inch, and mounting within an anti-reflective aluminum alloy ring. A Digital HT (High Transmission) multi-coating has also been applied to the filter surface to help reduce flare and ghosting for improved contrast and clarity. This is also paired with a titanium protective coating that guards against scratching and renders the filter easy to clean.