I'm doing a photo assignment that is going to involve dark settings with bad light. I'm using a film camera [Pentax k1000]. Are there any tricks to make sure that when I develop all my photos don't come out too dark? I'm going to use external lights probably to help the situation. What would be a good way to place them? Facing up towards the subject, facing down, straight on, to the side...? Any tips? Shooting a person.