Similar to the idea that a meal’s visual representation is equally responsible for the overall enjoyment of the dish, noise or sound is half the recipe when it comes to great footage.
Built-in microphones are convenient but are never the go-to option. These microphones pick up camera-handling noise and may be placed too far away to gather dialogue. In live music scenarios, these microphones pick up too much.
Quality sound relies on an external microphone attached to a camera, radio microphone or telescopic boom pole.
Microphones need to be isolated with a shock mount or suspension system to ensure non-interference of static or handling noise, usually made from thick rubber bands that hold the microphone in place.
For close-up or indoor shots, microphones are fitted with foam windshields. Outdoors, microphones don a furry wind cover to reduce wind noise. With an outer furry layer and inner sponge, these covers slow wind down and reduce low-frequency noise. Cameras are often equipped with low frequency, low-cut roll-off switches as well, but this can be resolved in post-production.
Cameras either have an XLR or audio jack connector for microphones, and each type of microphone should be matched with the interface. Most professional cameras have XLR connectors with switchable -48V supplies for shotgun microphones. These connectors have low-cut filters and variable attenuation (-50 db, -60db) to accommodate louder sounds.
Your choice of microphone plays a part in the style of sound produced. A camera-mounted shotgun microphone points the same direction as the camera, so any off-axis sounds would not be picked up.
Boom poles that point microphones directly at sound sources are fixtures in drama filmmaking, regardless where the camera points. These structures can also be tethered to the camera or external recorder by XLR cables. To avoid additional interference, avoid cheap cables and do not step on them.