When shooting in the field, you should only use the camcorder's built-in microphone as a last resort. It will pick up far more than you want.

On the other hand, if you are using an external mic to capture dialog, you should use the built-in mic on one channel and your external mic on the other. This way you will have a separate track of ambient or background audio that is separate from the dialog. In edit, you can blend in the background as you wish.

You can also use your camcorder as a tape recorder in the field. For example, if you were filming a scene where your actor exits a car, don't rely on the sound of the door closing recorded on your main audio, have the actor close the door again with the mic or camcorder held very close to the door. Maybe you do it 2 or 3 times at different gain settings. The point is, tape is cheap. It gives you more flexability in editing. It's also captured with the rest of your video so it's already there when you edit.

We always use a slate (clap board) when shooting and record takes by scene no. and take no. We have a PA list scenes and takes as they're shot, including time code. When the director is happy with a take, we mark the list. That way when we capture into the editor we can either enter in the start and stop times into the editor and only capture what we want, or capture all and delete by time code in edit. This saves a great deal of time.

If you don't have a slate, have your actor clap once and say loudly the scene and take number. This can be a life safer if your video and audio track accidently become out of sync.

Ray6