Canon Vixia HF G20 goes dark on its own even when it is in Manual Mode

[Nickcamera]

I have reset it to default settings and put it in manual mode and put focus on maual mode and for some reason when I am shooting a video it will automatically turn dark on its own. It starts out bright and nice looking and for some reason it goes dark in the middle of a shoot.

And I am shooting in a studio with controlled lighting and just of a person being interviewed. There is no changes to the light or any real movement from the person I am shooting. A very simple video shoot but for some reason the camera seems to darken on it owns.

Is there a fix or a setting I am missing?

[Wbaruch]

I am doing the same exact thing. Video taping interviews for my website. www.bluelinefutures.com click the research link. And look at the videos one is dark and another is light. We don’t know what we are doing differently. The lighting is controlled too with LED