Audio Basics
Sound has been described as being 50% of a movie. Obtaining good sound with your videos is a matter of knowledge and equipment. Let's start with some of the essentials. No matter what microphone you use, proximity is key to sound quality. You never want the microphone more than a few feet away from your actors if you are recording dialogue.
There are two types of microphones. Dynamic microphones can be handled without picking up additional sound from holding the mic. These are usually used by singers. Condenser microphones pick up sound well, but are sensitive to sound produced by anything, such as your hand, that comes in contact with them. They are the type of mic usually used when filming and therefore need to be mounted and isolated in some way. The microphone below is a condenser mic, called a shotgun mic, it is directional and will pick up sound from the direction it is pointed toward. This is good when you don't want to record noise from the sides or behind the camera. It can make dialogue easier to understand. When filming outside it is useful to use a windscreen to reduce the sound produced by moving air.
Condenser microphones need external power to operate. They receive it from a battery or from the device they are plugged into. This is referred to as "phantom power".
To keep your microphone close to your sound source you can use a boom mic, a clipped-on lavalier mic (wired or wireless), or mounted external shotgun mic (placed on the camera or on a stand). The microphone built into a camcorder or dslr (digital single lens reflex) camera is usually not very adequate at picking up sound, and its quality is often very tinny. All microphones produce self-noise that we hear as a hum or hiss. Some equipment can help to eliminate this hiss by amplifying the audio signal before it reaches the camera. This can be achieved with a decibel boost control on the microphone or with a preamplifier. When doing this it is helpful to turn down the gain or audio level in the camera, if possible. You want to keep the audio levels strong, but not maxed out as this can cause distorted sound. Some cameras allow you to monitor the sound with headphones to help.
It is desirable to record good audio in the camera along with the video as this can save a step later in what is referred to as post-production, when the video will be edited with computer software. It is possible, however, to record the audio separately from the video, and then sync it up later on the computer. When doing this it is helpful to create a sound spike that matches a physical movement. This can be done by clapping your hands, snapping your fingers, or using a clapboard.
It is desirable to record good audio in the camera along with the video as this can save a step later in what is referred to as post-production, when the video will be edited with computer software. It is possible, however, to record the audio separately from the video, and then sync it up later on the computer. When doing this it is helpful to create a sound spike that matches a physical movement. This can be done by clapping your hands, snapping your fingers, or using a clapboard.