g shock exposure changes
 

I've been shooting a series of clips with the camera mounted on cars and motorbikes.

I've noticed that whenever the vehicle passes over a noticeable bump the camera exposure changes (image gets darker) just for the period of the bump then reverts to what it was.

Has anyone else noticed this and is there any way to prevent it happening?

The camera is set on manual exposure during this.

Cheers

Geoff