With approximately twice the strength of the KR1.5, the B&W 46 mm KR3 (81C) Warming Color Conversion Multi-Coated (MC) Glass filter reduces blue and green. Even the strong blue cast of a high standing sun in a cloudless azure-blue sky, in regions with especially clear air, or the haze in distant views is removed very effectively. This filter also blocks disturbing UV radiation completely.
An 81C can also be used with electronic flash to reduce the amount of "blue" generated by the flash. The 81 series (81A, B, C, D and EF) allows you to choose how much warmth you wish to replace in the image.
Multicoated to minimize reflection at the filter surfaces which reduces flare and ghosting.
Note! Whereas the 81 Series of filters creates a feeling of warmth, the 82 Series creates a feeling of coolness