How to Get Rid of Automatic Gain Control on a Canon T2i

You'll need two stereo-plug-to-mono-jack adapters for the Canon T2i AGC workaround.

Canon's Auto Gain Control, or AGC, can't be turned off on the T2i camera: you need to do a little workaround to get rid of it. Left on, AGC creates a lot of hiss whenever there's silence during video filming. The hiss is time-consuming to remove in post-production. With a little tweaking and a few dollars' worth of electronics you can get rid of AGC yourself.

Things You'll Need

• 2 stereo-plug-to-mono-jack adapters, 1/8-inch
• Stereo-male-to-dual-female Y-adapter, 1/8-inch
• MP3 player, iPhone or iPod
• External microphone

Instructions

1. Record 20 or more minutes of a 440Hz tone in any audio recording program, or download such a tone from the Internet.

2. Load the clip on your MP3 player, iPhone or iPod, and set it to play on repeat.

3. Plug the Y-adapter into the audio jack on the left side of your T2i. The connection may be a little tight; check it periodically during filming to make sure it's secure.

4. Insert a stereo-plug-to-mono-jack adapter into each of the female adapter jacks.

5. Plug your external microphone into one adapter jack and your music player into the other. Make sure the music player is playing the 440Hz tone continuously. As long as the tone plays you won't record hiss during silence while filming.

References

• Dan McComb, Filmmaker: How to Really Disable AGC on Canon T2i

Resources

• Media College: Download Audio Tone Files