Digital camera IR-Cut filter
Description for IR-Cut filter
IR-Cut filter are used with color CCD or CMOS imagers to produce accurate color images. An IR cut-off filter blocks the transmission of the infrared while passing the visible. This can be done with two optical techniques: absorption or reflection. Absorptive filters are made with special optical glass that absorbs near infrared radiation.
IR-Cut filter are used to block or reflect infrared wavelengths but pass visible light. Mid-infrared filters are often used as heat-absorbing filters in devices with bright incandescent light bulbs (such as slide and overhead projectors) to prevent unwanted heating due to infrared radiation. There are also filters which are used in solid state video cameras to block IR due to the high sensitivity of many camera sensors to unwanted near-infrared light.