The B+W 67mm UV Black (403) Filter is a specialized filter used to block visible light while allowing UV A radiation (320-385nm) to pass through. This filter differs significantly to the more well known UV filter, which does the opposite by blocking UV radiation. The UV Black filter visibly appears completely black and is used in combination with specially sensitized films for applications such as forensic photography, material research, and fluorescence photography. Depending on the illumination and materials being used, the filter factor ranges from 8 to 20 (3 to 4.3 stops).
B+W filters are constructed from high quality Schott glass for increased optical clarity and color fidelity. They feature a brass filter ring for durability as well as jamming prevention.