Continuing blogging about my experiments with the new Canon EOS 550D: my first tests with the video audio point out that there is actually no sense in attaching an external mic to the camera right now. The AGC (automatic gain control) issue is much worse than what I thought. Here are two tests, the first with the internal mic, the second shot using the Röde Stereo Videomic, and in this latter one the “hiss” is almost intolerably loud:
Apparently the sensitivity of Röde is different from the internal mic, and the automatic gain control keeps on boosting the sensitivity up, until the audio becomes saturated with the background hiss.
There are a couple of potential work-arounds to this, but neither makes me very happy. The first one is to wait for a patched firmware to Canon EOS 550D; it is unlikely that Canon will provide a way to turn off AGC through the official firmware, but there are unofficial projects working on this kind of things. The most famous of these is the Magic Lantern project, but it is highly uncertain whether they will ever produce a hacked firmware for EOS 550D (the main focus is on 5D). More:
The second way that I know about is the “bypass trick”, where you fool the AGC to keep down by pushing synthetic tone to the other audio channel, and record your movie to the other channel. In the post-production you can then remove the extra channel. There is this video that explains the technique:
Neither way is that kind of quick fix that I would be hoping for (and I am not interested in plugging in extra sound sources every time I will be recording a short video clip), so any further ideas or advice on how to work around the AGC issue in EOS 550D are highly appreciated.