Infrared Cut Filter
A filter bonded in front of the sensor that blocks infrared and ultraviolet light to which silicon is sensitive but the eye is not.
Measured in
nm
In depth
Silicon responds well beyond the visible spectrum, so without this filter black synthetic fabrics would photograph as pale and foliage would render oddly bright. Removing the filter is the basis of infrared conversion, and its presence is why infrared photography on an unmodified camera needs extremely long exposures.
Examples in practice
A camera with its infrared cut filter removed photographs foliage as brilliant white under a deep red filter.