Audio is just as important as video in most productions, and to showcase your video well, you need to consider which mic works best for your audio.
The built-in microphones of camcorders are really quite remarkable devices that do a very admirable job most of the time. This is especially true when you consider the wide latitude of shooting scenarios they are designed and expected to perform in. But for truly optimal sound they fall a bit short; to get really superlative audio you have to use an external mic.
There are several different types of auxiliary camcorder microphones available, and knowing what makes them different will help you in deciding which type(s) will be right for you and your shooting requirements.
The Big Three
Basically, there are three main types of camcorder microphones to consider: the omnidirectional, the unidirectional and the cardioid. Let's take a closer look at each one.
Omnidirectional microphones have a pickup pattern that captures sound from all directions, hence their name. Most built-in camcorder mics are omnidirectional and they're best suited for recording sound that is in relatively close proximity to the camcorder.
Unidirectional microphones, as the name implies, record sound coming from one direction – directly in front of them. These are especially useful when you desire to isolate specific sound, such as an individual's voice, from the other ambient sounds in a scene.
Cardioid microphones are so-called because their pickup pattern is somewhat heart-shaped. They pull most sound from the front and sides, and a bit from just behind them. Most handheld, or "stick" mics used by reporters are cardioid.
In addition to the types of microphones, you'll also have to choose the mount type of the mic.
Camcorder-mount microphones are mounted directly on the accessory shoe of the camcorder. With the use of an extension cord, they can also be easily mounted off or away from the camcorder or even hand-held if required or desired for your application.
Hand-held microphones are ones that are literally held in your hand or mounted on a microphone stand with a clip. These mics are very versatile but, due to their size, are difficult to hide in a shot.
Shotgun microphones work in situations when you can't place a mic directly in front of your subject, since they only pick up sound from where they are aimed. Some people think they can pick up long-distance sound, but they can't, they're just highly focused unidirectional.
Lavalier microphones are small and can be clipped to a jacket, necktie or blouse. Newscasters and talk-show hosts and guests frequently use lavalier mics since they are unobtrusive.
Making the Connection
There's yet another choice you'll have to decide on: whether you want a cabled (hard-wired) microphone or a wireless one.
A cabled microphone connects to the camcorder via a mic jack and cable. The length of the cable determines how much mobility the camcorder and/or the subject has. Cabled mics can sometimes pick up interference from electric lines and fluorescent lighting, but this usually isn't a major concern. Some cabled mics run on phantom power, which means power through the camcorder. The advantage of these, especially in a controlled environment like a studio, is you don't need to worry about batteries dying or a signal fading.
Wireless mics, on the other hand, send the sound signal via a transmitter to a receiver that is connected to the camcorder and, since there is no umbilical cable to contend with, they offer a lot of freedom of movement for both the subject and the camcorder. This freedom isn't without a price, however. First, the transmitter isn't always easy to conceal on the subject, which may or may not be a big concern to you. Second, since the audio is being transmitted via radio waves, it may be subject to interference from other electrical devices close to the transmitter or the receiver or from other devices that are also transmitting close to it.
The Cost Factor
The price of microphones can range from about $30 to several thousands of dollars. Just like everything else, you get what you pay for when it comes to microphones. There are obviously some significant differences between a $49 microphone and one that costs $490. The difference is usually in the quality of construction, the materials the mic is made of and, most importantly, the sensitivity and dynamic range. These last two items become particularly important if you're recording sound that spans a wide spectrum of volume and frequency, such as recording a string quartet. Sensitivity and dynamic range are less of an issue for recording speech and other normal' sound.
The old adage penny wise and dollar foolish' comes into play here when shopping for a microphone. While you can get cheap mics in the electronics departments of the big-chain discount retailers, you'd do better in the long run to consider going with a well-known and established brand name mic manufactured specifically for videography and filmmaking. They cost a bit more, but you get what you pay for.
What you are using the mic for predominantly, how you want to mount it, whether you need to go cabled or wireless and, ultimately, how much you can afford – and want – to spend for a microphone are questions you should consider in depth to determine the best microphone solution for you. At that point, you'll be in a better position to shop for price because you'll be an educated consumer.
Tom Benford writes about video, photography, filmmaking and myriad other subjects and has authored more than a dozen books.
Click here to download a PDF Manufacturer's list of Videomaker's Microphone Buyer's Guide.