The Lee 81 Series of filters control the bluish coloration that affects daylight film. They can also remove excessive blue from the effects of electronic flash. Good for general scenics when the photographer wishes to remove the bluish cast from open shade or just add warmth to the photograph, with an 81EF having the greatest effect.
Whereas the 81 Series of filters creates a feeling of warmth, the 82 Series creates a feeling of coolness.
Color Compensating Filters - Some photographic situations require specific color corrections. For example, when shooting daylight film under fluorescent lighting, some magenta correction is needed in order to remove the greenish tint that would otherwise appear. The amount of color correction required is most accurately measured via a color temperature meter.
Color Compensating filters are made of either resin or gelatin and are available in the three primary colors: Red, Green, and Blue; and in the three secondary colors: Cyan, Magenta, and Yellow. A typical designation for one of these filters is CC30M; The "CC" stands for Color Compensating; The "30" stands for a density of 0.30 and the "M" is for magenta.
This filter combines an 81 conversion filter with a CC05C (Cyan) Color Compensating filter.