Q: “We’re making a low-budget film and my make-shift boom operator (roommate from college) needs to know how close to get the mic to the actors. What should I tell him?”
A: Some of this, of course, depends on the microphone itself. Saying that, the shot and composition of the shot is God when it comes to filming (or video taping). So, the best rule of thumb is to have the microphone at the end of your boom be a low as possible without entering the shot. How can you do this? Place a strip of white tape on the tip of the windscreen of your microphone (or somewhere in that area), have your boom operator dip the microphone completely into the shot, then slowly raise it up until the camera operator tells you that he can no longer see the microphone or the white tape. Most camera operators will not be concerned with your microphone, but the white tape will be their guide to communicating with the director and boom operator. Finally, if the camera intends to move at all in a given take, be sure your boom operator practices his movements WHILE the camera operator is practicing for his shot.