Your Camcorder's MicrophoneI don't want to give the impression that a camcorder's built-in microphone is a flimsy afterthought. On the contrary, it's a sophisticated device that does the best it can given the circumstances. Where it falls flat at times is with its placement: Because camcorders are so small, there isn't much room for a microphone (Figure 5.2), so you're bound to pick up sounds that the camera is making (such as the motor advancing the tape, or the zoom control adjusting the lens). Figure 5.2. The camera's built-in microphone is good, but it's susceptible to picking up noise from the camera and doesn't record distant subjects too well.
Another limitation is distance. The most important factor when recording audio is the distance between the microphone and subject the closer the better. If you're filming a birthday party, for example, you're likely to be right in the action and will pick up audio pretty well. But what about when you're doing an interview? You want the person's comments to be picked up clearly, but you don't want the camcorder to be in her face. If you're shooting from a moderate distance away (see "Depth of Field" in Chapter 2), the microphone won't pick up the sound clearly. 12-bit versus 16-bit audioMost likely, your camcorder includes the option to record in 12-bit or 16-bit audio. When you're recording in 12-bit, the microphone is grabbing sound in stereo and saving it to two separate channels (left and right), leaving two more channels to record more audio in the camera later. If you choose to record in 16-bit audio, the quality is a bit better than what you'd hear from a CD you're sampling more audio data than in 12-bit mode. (See this book's companion Web site at www.necoffee.com/imovievqs/ for samples of each output.) However, that extra data occupies the available channels, so you can't add more audio to that footage (but see the tip on the next page). More data also means that your footage will take up more disk space in iMovie than 12-bit footage. Wind Screen modeHere's a good general tip: read your camcorder manual before you go on vacation. If I hadn't been in such a hurry to take a break, I would have discovered the Wind Screen feature of my camcorder, which does a decent job of cutting down the extra noise produced by wind blowing into the microphone. It's not a perfect solution (what is?), but it would have made some of my footage sound less like I was in the middle of a tornado. Tips
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