building leaders for multi-site churches
How many cameras really depends on what you want your end product to be like.
At Harvest, we used multiple cameras, but only during the music part of the service, but when it came to the teaching portion, we used 1 camera that is a fixed "shot" that is displayed a full body shot. That shot was displayed on large screens at campuses to give a "virtual teaching" effect.
At Cross Point, we are currently using one camera that displays an upper body shot and moves with the speaker. The primary reason is for imag for the main auditorium. We are adding at least one additional camera soon to enhance our recordings for our upcoming internet campus.
Hope that helps some.