Using a gray card with the HF100 from Martin Koch on Vimeo.
A gray card is a great way to adjust a "technically" correct exposure in controlled lighting conditions that don't change during shooting. It can also be useful to set the exposure in difficult scenes like e.g. an object in front of a bright background. You'll find gray cards at any serious photo store.
Put the gray card under the same light as your main object. Point the camera at the card, step close or zoom in on it and adjust the exposure in manual mode.
On the HF100 there's no manual mode. You can either lock a certain arperture (Av mode) or shutter speed (Tv mode). In the video above I show you how to display the exposure settings, how to lock the shutter speed to 1/50s and then how to also lock the arperture (and gain) setting chosen by the HF100.