If you are playing a standard RightBooth event, you will notice that the webcam is turned on pretty much all the time.
The general rule is that the webcam is switched on whenever an event screen is displayed that contains a webcam item.
To see this, open any standard event, visit the Screen Editor and look at the Start screen.
Here you will see the screen contains a webcam item which provides the live feed from the camera.
You can easily turn the webcam off by removing the webcam item from the Start screen.
Then when you play the event:
It's as easy as that !