I've been quite interested in the video capabilities of my 7D, but the audio always turned me off. I did some initial research, and found that most people were buying a sound recorder (like the Zoom H4n) and syncing the audio in post. The Zoom H4n is not necessarily cheap, and I didn't want to fool with syncing the audio in post.


Recently, I started looking into different mics that I could simply plug into the 7Ds mic port and place on the hotshoe. I wanted a solution that would be easily workable by one person (yes, having someone boom a mic is ideal, but not practical in many situations). As I was pouring over tons of reviews, I realized that Canon's Automatic Gain Control was still going to cause audio issues even with a decent mic. So what's the point in buying a decent mic to plug into the 7D if the camera is going to basically ruin the audio anyway? Thankfully, I came across a workaround for dealing with Canon's AGC. The following three videos explain (with varying degrees of detail) how to cancel out Canon's AGC and easily fix it in post.





This video got the ball rolling.


[View:http://www.youtube.com/watch?v=91xw_NX0Qm8]





Here the narrator has to do a few more steps to cancel out AGC with the popular Rode VideoMic.


[View:http://www.youtube.com/watch?v=fnQAd23wFes]





In this video, the same guy from above reviews a Y splitter cable that serves the same function as the one he soldered together.


[View:http://www.youtube.com/watch?v=SqVu4cDvjmg]





Another method of piecing together an AGC solution when using the Rode VideoMic. You'll likely have to pause the video several times as it runs through the parts/setup very quickly.


[View:http://www.youtube.com/watch?v=Qq-JXngqypM]





I think this is a novel technique for dealing with the problem, assuming Canon doesn't add AGC control in a future firmware update (which I highly doubt). I plan on buying a decent mic with the aid of some B&H gift cards I got for Christmas, and will likely try this out.