B+W 55mm KB20 Cooling Color Conversion Glass Filter (Slim)

The B&W 55mm KB20 Cooling Color Conversion Glass Filter (Slim) is the correct filter to use under illumination provided by 40-150 Watt household incandescent bulbs. It is also for correct color conversion with transparencies that display technical interior, architectural photographs or reproductions.

It should not, however, be used for moody interior pictures because unlike the KB15 and KB12 filters, the KB20 corrects the light to a neutral balance, eliminating the warmth that we might intuitively expect from bulbs.