When I do a 2 or 3 camera shoot I turn on all the cameras and leave them going until the end. In post, after the sound is sync’d, I choose what to show at any particular moment. I never point the camera at slide presentations unless it is not available. I set one camera as wide at the back, usually unmanned, and zoom in or follow the speaker with another. If I use a third camera its for a side view, slightly back of the speaker to show some audience (as long as the audience is dark).
