I have just received my X20, and while the battery was charging, looked around on the camera. When I looked in the optical viewfinder, I got a little bit disappointed. The view was dark and not clear at all, not what I had expected. Then I plugged the charged battery back in, and took the first picture, and to my surprise, the viewfinder was now very clear and bright. I pulled the battery, and the OVF was again dark and muddy. What's happening here? I know the OVF have an electronic layer, but does that mean that the camera use battery, even if it is off?