Sumix SMX-M7xx - Manual (Page 70)

IR-cut Filter : When to Use
70 SMX-M7xx Series USB2.0 Camera User Guide
When to Use
The IR-cut filter can be used for both color and monochrome SMX-M7x cameras.
Using IR-cut Filers with SMX-M7x Color Cameras
IR-cut filter is a color filter that blocks infrared light. Since the SMX-M7x color cameras
are sensitive to IR-light, use the IR-cut filter with color camera models to make colors of
the image more realistic.
Many light sources, including the sun, emit infrared light, so the color camera in daylight
will see a significant amount of infrared light without the IR-cut filter. As a result, strange
and non-realistic colors appear.