Mounted Infrared (IR) Filters are frequently used as heat-absorbing filters, letting the visible spectral range pass while the infrared rays from 780nm and above are firmly blocked. These infrared filters are often used to protect IR-sensitive sensors or in illumination systems. Mounted Infrared (IR) Filters use IR-grade fused silica, which differs from UV-grade fused silica by its reduced amount of OH- ions, resulting in higher transmission throughout the NIR spectrum and reduction of transmission in the UV spectrum. UV/IR-Cut is a multi-coated interference filter that completely blocks unwanted UV and IR radiation. It is especially recommended for applications where digital image sensors have not been fitted with an IR protection filter (or it was removed).
Note: The transmission characteristics can be permanently changed for intense radiation from UV sources with wavelengths below 320nm (i.e., Xenon lamps).
There is little effect on off-axis angles; however, it is not recommended for extreme angles of incidence. UV/VIS-Cut filters, also known as Infrared (IR) Pass Filters, absorb most of the ultraviolet and visible region and transmit the infrared region. For infrared images that combine visible and infrared light, we recommend the R-72 Infrared (IR) Pass Filter (which passes 720nm and above). Note that lenses are typically designed for the visible spectrum, so focusing adjustment is required to obtain clear images in the infrared.