Here’s a quick and inexpensive way to trick the automatic gain control (AGC) in a DSLR from increasing the volume during the quiet parts of your recording.
It only works on cameras like the Canon 7D and T2i which have a microphone input. Also, the AGC function is just one reason the audio recorded on these cameras is less than great.
Pro audio recorders capture the sound in high resolution. Meaning that they use high sample rates and more bits per sample to capture a more accurate version of the sound. DSLR cameras use moderate sample rates with much fewer bits per sample.
What this means is that the audio may sound okay until you start to work with it in post production. Then, just like a poor quality video image, you’ll find you can’t do much with it.
So, give this trick a try to improve the quality of the audio recorded in your DSLR HD camera. And, if you’re out to make a film that you want to be as good as possible, spend the time and money to capture the sound with a professional microphone and recorder.
Yes, you have to lock the second audio track to your video in post but the results are well worth the effort.