Why does my Canon Vixia HF G20 go light and dark on it's own even when I have it in manual mode?

[Evolving]

Hi, I have taken the training wheels off, i.e., switched from auto to manual mode on my Canon Vixia HF G20.  So far, it's been going well.  I was hoping that the switch would take care of a real problem I've experienced in auto mode.  The captured video seems to cycle from light to darker.  This happens even when the person isn't moving.  I don't think it happens as much on a tight shot, but does on a wider shot.  Any suggestions would be appreciated.  Thanks

[Nickcamera]

I am having this same issue. Is there a fix? Or a setting that I am missing?

[IamintheUK]

If your G20 is like my G40, when it is set to manual mode and you power off and turn it on later, the exposure control reverts to auto. So you have to set it to manual exposure each time you power the camera on. The effect you are seeing is most likely the auto exposure working.

[Nickcamera]

Yup, mine does that! That has to be it. Thanks