These caps can be used to block the infra-red light made by the night vision lights that are attached to this raspery pi camera. This saves taking them off when you don’t want to use them but stops the purple tinge to the footage in low light conditions.
If the light still passes through the filament, you can use aluminium foil on the inside to make a layer the light can’t pierce.
The author marked this model as their own original creation.