Description The B+W 092 has become a popular filter for IR photography. This nearly opaque filter looks dark purplish when held in front of a light source and blocks the visible spectrum up to 650 nm. It passes only 50% of the radiation just below 700 nm and from 730 nm to 2000 nm, transmission is greater than 90%. As the sensitization of IR black + white films barely extends beyond 1000 nm, the red portion that is transmitted still makes a relevant contribution to the exposure. The filter factor is in the range of 20 to 40 but largely dependent on the illumination present and on the characteristics of IR film or IR blocking properties of the sensor.
B + W 77mm Infrared Filter # 092 (89B)