B + W 82mm 80C / 80D Tungsten to Daylight Conversion Wide Angle Slim Mount Glass Filter (KB6)
"80" series filters are color conversion filters for the use of daylight type color films with artificial light source.
The 80D is a middle-blue filter that reduces the strong red tendency of morning and evening light. This filter is used to reduce extreme yellow, orange and red elements of scenes. Filter factor is approx. 1.5.
80D increases color temperature from 4100-5500 degrees Kelvin.