While filming various scenes using my GH1, the histogram is excellent for establishing the correct light for a shot. However, when trying to film a scene in a dark room (eg. a room during night-time), the histogram reads that the light in the room is too dark (under exposed) and I need to brighten the room up to get the right reading on the histogram. This does away to the whole concept of shooting a dark room because the room just becomes a normally lit room. Am I relying too much on my histogram for these kinda shots or should I just bring in additional lighting (eg. a soft blue light for the night-time effect)?