What type of external camera microphone do I need?
If you record conversations between 2 people or an interview, you choose a shotgun microphone. Most shotgun microphones have a supercardioid directional characteristic that blocks sounds from the sides and the back. This allows you to record isolated sounds from a short distance. These microphones are also very suitable for recording an audio track in a studio.
Sometimes you want to include ambient noise in your recording. For instance when making a documentary in which you record in a room. Here, you also want to record some ambiance. In this case, you use a stereo microphone. This microphone captures sound as we hear it with 2 ears. The 2 internal microphones both point in one direction which allows a mix of the ambient noise to be registered.
As soon as you make a speech, it is often not possible to place your video microphone close to the audio source. A handheld microphone is also not always suitable because of the limited freedom of movement. In these situations, you use a lavalier, also known as a lapel microphone. This microphone only records what the wearer says. When recording an interview, you use a discreet lavalier that is invisibly placed on a jacket.
Omnidirectional, cardioid or supercardioid?
An omnidirectional microphone absorbs sound all around. The signals come in equally well from all sides. This makes an omnidirectional microphone very suitable for absorbing ambient sounds. When it's placed on a jacket, the speaker with this type of microphone can move his head freely without any sound dropping.
If you want to record as little as possible of the ambient noise, use a cardioid microphone. This microphone is most sensitive to the sound at the front due to the kidney-shaped recording area. Sounds coming from the rear are blocked. To a lesser degree, signals from the side are also not included. The recording angle of this microphone is 180 degrees wide.
This microphone is similar to the cardioid microphone but is a lot stronger. A supercardioid microphone is very insensitive to sounds from the side and back. The sounds are recorded most strongly from the front. That is why it is important that the microphone is placed as close as possible to the audio source.
Determine directional characteristic
The directional characteristic of a microphone determines from which direction the microphone is most sensitive. Some microphones are more or less sensitive to sounds from the side or rear. So choose an omnidirectional, cardioid or supercardioid camera microphone that best suits your needs.