Infrared (IR) cut-off filters 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. Reflection type filters are
short-pass interference filters that reflect infrared
light with high efficiency.
We offer two types of absorptive IR cut-off filters, IRC20 and IRC21, and two
types of reflective IR filters, IRC30 and IRC40. The IRC40 is a specialized
reflective filter suitable for day/night cameras that allows both visible and
850nm infrared LED light to transmit. The absorptive filters are recommended for
CCD imagers while the reflective are recommended for CMOS imagers. Our standard
off-the-shelf filters are listed below. If you need a custom filter, please
contact our support.
Narrow down IR cut-off filter choices by the following options:
|Default effective aperture
||Schott D263T or BK7 equivalent for coating filters
Absorptive optical glasses for absorptive filters
||Coating filters: Schott D263T glass: 0.3, 0.5, 0.7 and 1.0mm. Other
thickness available for BK7 glass
Absorptive filters: determined by the absorption requirement
||60/40 scratch/dig. Grade 20/10 or better is
also available on custom basis.
|Spectral transmittance (typical values, not specifications)