The acoustics are important for a good film

The sound is just as important in film as the picture and should ideally sound natural. So you have to be able to react flexibly to environmental influences. The camera's internal microphone picks up sound broadly, so it picks up everything that's happening around. External microphones can also be connected to the camera without any problems. Before recording, you should therefore think carefully about which microphone is best suited for the right sound.

However, the sound recorded with the internal camera microphone can cause problems due to the direct connection to the housing. With older devices, for example, you can hear the drive noises or just touching the camera makes unpleasant noises. If a tripod is used, the impact noise can be noticeable here. The advantage of external microphones is therefore obvious. The better the microphone suspension, the less unwanted noise. Good suspensions are realized by rubber bands that are tightened against each other in such a way that the microphone can vibrate freely in the middle and has no direct contact with the solid components of the housing. This is what is called a "spider" in audio engineering.

The background noises such as the wind, rain, etc. remain, especially when recording in the great outdoors. For this there is, among other things, a special protection made of fur, which is also called "cat" in film language. Popping and hissing noises occur when recording voice. A foam cover helps here, or a spacer or pop filter in the studio. Every microphone has a specific pickup and directional characteristic. The sensitivity of the microphone is particularly high in one direction. An omnidirectional microphone is equally sensitive in all directions and is mostly used to record sound atmospheres, music and noises. With the cardioid characteristic, only the front is recorded and unwanted noise from the direction of the cameraman is not recorded. The left and right sides are only covered 50%. As an increase, there is the supercardioid. A figure-of-eight microphone is equally sensitive to sound coming from the front and rear, while sound coming from the sides is extremely strongly suppressed. In practice, such microphones are less suitable for film recordings, as they sound unnatural to the human ear. One finds such microphones in the recording technology of music.

The closer the microphone is to the sound source, the better the sound and the less background noise. If the microphone is attached directly to the camera or even built in, you have to get close to the subject. A distance of one to two meters is good, it can also be closer. In order to have a microphone in the picture, so-called boom poles are often used, whereby the microphone is held over the speaker and therefore another person is necessary here. In exceptional cases, the boom pole can be attached to a tripod.

Stereo or monaural?
For film recordings, there is the option of filming in either stereo or mono. Noises and sounds should always be recorded in stereo because they can be better distributed in the sound space in the later mix with the music. The same also applies to high-quality dialogues, for example in a feature film, when the subject moves through the picture. A mono recording is sufficient for simple voice recordings, e.g. in an interview. During the recording, the sound should be monitored through headphones. However, the volume in the headphones has absolutely nothing to do with the recorded sound level and is only used for checking. When it comes to modulation, the optimal level should be reached as often as possible, but exceeded as rarely as possible. Where the optimal level is depends on the equipment. Absolutely avoid oversteering and prefer to leave room for improvement. However, too little level is at the expense of quality. Normally the working point is defined as 0dB, then the "headroom" is up to +6dB.