Shotgun Microphone Techniques
Most sound people prefer to use a shotgun microphone over a Lavaliere (link to Lavaliere article) in most cases. A shotgun microphone (mounted on a boom) is more realistic in terms of echoing how someone sounds in a room. The room acoustics are heard in the sound that the boom mic picks up. A wireless microphone captures sound in a manner that isn’t as realistic. It often sounds controlled and reflects its placement in a room rather than the dynamics of the room. Also, when working in a studio for live TV, it’s easier to use a shotgun in terms of having to have less EQ changes.
The difference between the sound of a wireless Lavaliere microphone and a boom mounted shotgun microphone is most apparent when mic-ing several people delivering dialogue. If a wireless microphone is placed on each of the people, then the sound is very out front. Each of the people sound as if they were recorded in a small booth by themselves. The boom mounted shotgun will included the dynamics of the room. This brings us to the question, why would we then ever want to use a wireless lav microphone? News and interview shows featuring talking heads fair better with lavs. Also, often it is difficult to choreograph the appropriate movement of a boom microphone.
You can have an outstanding shotgun microphone such as the Audio-Technica 4071 shotgun but if your boom person is not capable, then you’re in trouble. On live TV shows, get a script to your boom person at the same time you deliver it to your actors. The boom person has to coordinate their movements with the movements of the actors and cameras. Not only is it important to keep the shotgun pointed toward the person delivering dialogue, it’s important to keep it out of camera view. If it’s a wide shot, then it is more challenging to keep the boom out of the shot. The boom person must follow the script rapidly so they can quickly aim the shotgun toward the next speaker. Their job requires attention to detail and manual dexterity. It’s not easy to guess the aim of a shotgun mic at the end of a 26’ boom.
The same logic that applies to studio TV shows applies to most film projects. Some lighting rigs contain lights such as Varilites that have lots of fan noise. When you encounter this situation try several shotguns and look for one with great off-axis frequency response.
If you have several people talking on camera (drama or interview show) and they are all wearing wireless mics, there is a chance that they will either step on each other’s lines or talk at the same time. When this happens, the other talent’s lav mics pick up the other dialogue as well. The sound mixer will attempt to prevent this but it is difficult. This doesn’t happen when you’re using a shotgun microphone on a boom.
A final reason for using a boom person is that some talent refuses to wear lavaliere microphones. Perhaps it’s too much of a distraction.