A professional videographer should use a modern video camera with 3 CCDs that delivers “broadcast quality”. The smaller cameras used for wedding and event video are not much larger than a typical consumer video camera, and provide reasonable image quality in moderately dim (if not “dark”) conditions. A camera mounted on a tripod will give the most stable image and is preferred for the ceremony. Monopods or hand-held cameras are most frequently used at receptions for the best angles on dancing and spontaneous action. Shooting with a moving camera in a live event without recording shaky video does require a skilled operator.
Using at least two cameras is particularly recommended for the ceremony, since this can provide good views of the entrance, ceremony and exit without requiring a camera to be directly beside the couple. More than one camera angle also provides a much higher liklihood of a smooth finished video since this is a “one-take” event and unplanned incidents often happen, for example a photographer, guest, or wedding party member may block one camera view at times.
If you want complete coverage, you will find it difficult with one camera. Things often happen in more than one place at the same time, or you will want shots of different people who are far apart. For example, the bridal procession looks nice interspersed with shots of the groom and congregation watching. This is all but impossible to achieve smoothly with one camera.
It’s not hard to move up to two cameras — one of them manned and the other locked off on a wide shot. For example, you could position yourself near the aisle with the manned camera and have a static wide shot set up from the back of the vanue. As you move to a new location (e.g. the reception), begin by setting up the static camera and hit record. You are then free to roam about with the manned camera.
The next improvement would be to have both cameras manned. After that, you could add a third unmanned camera. Three cameras should be ample for most weddings.