Sumix SMX-M7xx - Manual (Page 72)

IR-cut Filter : How to Use
72 SMX-M7xx Series USB2.0 Camera User Guide
3 Use a needle-like tool (e.g. tweezers) and screw the IR-cut filter in:
Note: The latest SMX-M7x color cameras have blocking elements on the inner thread to avoid the IR-cut filter falling on
the sensor. The previously manufactured cameras do not have these blocking elements, so when screwing the IR-
cut filter into these cameras, make no more than 10-11 full turns.