The Hitech Color Temperature Camera Filter Kit - 85mm is a color temperature conversion kit consisting of 4 camera filters.
The 85b Amber filter is used for exposing type B tungsten materials in daylight. It performs a significant color temperature conversion of 5500-3200K with an exposure of +2/3.
The 85c Paler Amber filter is sometimes preferred for exposing Type L tungsten materials in daylight. It performs a significant color temperature conversion of 5500-3800K, with an exposure of +1/3.
The 80a Blue filter is used for exposing daylight-type color materials under 3200K tungsten illumination. This filter converts temperature from 3200K to 5500K, with an exposure of +2.
The 80c Blue filter is for use under 3800K tungsten light. It converts temperature from 3800K to 5500K, with a +1 exposure.