It generally only takes a video shoot or two before you realize that the weakest link on your camcorder is the microphone. Don't worry: It's not you, or really your camcorder for that matter, just the simple fact of life that all onboard microphones are lousy.
This leaves you with two alternatives for capturing higher-quality audio: get really, really close to your subject, or use an external microphone. Assuming that close proximity is not always an option, you'll almost certainly end up going with the latter approach, which is also the more complicated. What do you need to know to do on-site sound right?
We'll start with a brief inventory of your camcorder, which will tell us the type of microphones you can connect to and the equipment you'll need to do so. Then we'll survey the most popular types of microphones and their uses. We'll also run through several common shooting scenarios with specific recommendations for microphone setup.
Note that there are myriad options for working around your camcorder's microphone. In general, I looked at options that were the least expensive, could be operated by the camera person and easily carried with, or attached to, the camera. If you're permanently mic'ing up a room, you should consider a different range of options. But if you're assembling a kit you can afford, take on the road at a moment's notice, and adapt to your next shooting environment, you've come to the right place.
BeachTek, Shure, and Sony provided most of the equipment we tested in this article, which is why their names keep popping up in the recommended equipment list. While they're certainly not the only equipment suppliers out there, we're more comfortable recommending equipment that we've used in the testing described below and several other shoots than passing judgments on microphones sight unseen—or sound unheard, if you will.
There are two ways to connect external microphones to camcorders, though not all camcorders offer either or both options. First, of course, is your microphone port, which comes in two general categories. One is an XLR connector, which is typically available only on high-end prosumer and professional camcorders. The other is the more typical 3.5mm stereo connector (also called a 1/8" connector), which is found on most consumer camcorders.
My Sony DCR-VX2000 camcorder offers both MIC and LINE input, while the vast majority of consumer cameras offer only MIC input. Microphone-level input is the output from the inexpensive, primarily unpowered microphones like those you may have used to record audio to your computer. They're inexpensive, and push out a very weak signal, like a few ten-thousandths of a volt. In contrast, LINE power is produced by a powered sound system like your stereo or a professional sound system. The signal is much, much stronger.
If your camcorder has a MIC input (which it probably does), it should work well with many of the microphones discussed in this article. However, if you ever try to connect your camera to a professional sound system, like that used at a speech or conference, you'll need to reduce the LINE output to MIC level (more on this in the scenarios below). Otherwise, the signal will be too strong for your camera and will produce distortion and possibly damage your camera.
The Sony camcorder, not atypically, also supplies plug-in power to power certain microphones. Specifically, lavaliere and boundary microphones use "condenser" pick-ups to acquire and convert sound to electrical signals. Unlike dynamic microphones, which are driven by magnets and sound waves, condenser microphones need electrical power to produce a signal.
Connect a condenser-type microphone to a camcorder without plug-in power (also called "phantom" power), and you won't get a signal. There are other alternatives for powering these types of microphones, but before buying, it pays to determine whether your camcorder has plug-in power or not. Generally, if it doesn't say so on the microphone port, it doesn't, but check your camera's documentation to be sure.
You can also attach a microphone to a camera if it has an intelligent accessory shoe. An accessory shoe is a bracket that sits atop the camera for holding accessories like lights and microphones. Not all cameras have accessory shoes, and not all accessory shoes are intelligent, meaning that they can provide power, control, or both to installed peripherals.
In Figure 1(http://www.emedialive.com/Articles/ReadArticle.aspx?ArticleID=8777), the camera on the left has an accessory shoe, but it's not intelligent, just plain metal on metal. It can certainly hold a camera or light, but it can't send power to the unit, or, more importantly, accept the audio back into the camera and actually use the microphone.
On the right, you can see the metal connectors beneath the covering I've pulled back, which indicates that this accessory shoe is intelligent and can power and communicate to a microphone and flash attachment.
Typically, if the accessory shoe is intelligent, the camera vendor will offer at least one optional microphone, but check your camera vendor to be sure. When available, these microphones are easy to install and use, relatively inexpensive, and can noticeably boost sound quality over that of the embedded microphone.