David, I was also wondering if you could give me some advice on this.
A while back, I was helping someone else on an amateur short. I was talking to the DP of that project, who isn't a professional, either. Personally, I thought both him and the director were talentless and unqualified after working with and getting to know them more (I'm usually not this negative, but I really just didn't have too much admiration at all for them). Anyway, I told him (the DP) I had a project I wanted to make, and I was having a conversation with him about the lighting I wanted. This is a film about a detective investigating a series of bizarre murders. I told him I wanted generally harder lighting, moody, with a considerable amount of contrast in the frame, and especially during the close-ups on the actors' faces. He said it was a bad idea, because using hard lighting would cause the innocent characters to look creepy and guilty. I said to him, "well, first of all, you don't know if he/she is guilty or innocent".
Second, I explained that I wanted the light to be similar to the C.S.I: Vegas style, where there's a considerable amount of contrast and hardness. The guilty and the innocent don't look noticeably different, in terms of the lighting on their faces (at least not to me when I watch, but then again, I'm not really experienced or a professional). The law enforcement characters and the suspects look about the same. I also said I thought it'd be better if the light were to treat both actors/characters roughly the same, and that the scene, itself or the mood of the particular scene was the factor in how the lighting scheme should be decided and not the specific character. Or perhaps, the physical setting of the story (for example if two characters are talking in a kitchen room) should also influence the lighting scheme. The lighting should look like the kitchen light in the story setting is lighting up the shot (whether it be the actual kitchen light itself or a more powerful, artificial set light pretending to be a kitchen light). I think C.S.I does this a bit, since they have elaborate and cool production designs. If a coroner's light is shining on a dead body, the examiner's face is lit up like that morgue light splashing off the coroner's table.
I also mentioned that it wouldn't necessarily be a good idea, regarding lighting continuity if the light (that could very easily be coming from a light that's a part of the setting in the story, or a light that pretends to be so) treats one actor differently that another actor. It wouldn't make any sense, scientifically, if the light is coming from an angle and hits the actors' faces from roughly the same angle when they're positioned roughly the same distance from the light source, whether it be the actual artificial light used on set, or the light that's a part of the story setting. The only response I got from him was, "you don't want your innocent characters to look guilty".
One example I did notice, if you ever watch that movie, Just Cause, (the movie with Sean Connery and Laurence Fishburne), there's a particularly interesting scene between Sean's character and Ed Harris, who plays a psychotic murderer. Both characters have high contrast and hard light on their faces. However, Ed's character seems to be even more contrast and harder light than Sean. I'm assuming this was intentional? There's one shot where Ed Harris blows up in anger, and right there, he bursts up standing, and all of a sudden his eyes and face just make him look almost like a monster, with the particular lighting scheme they used (which made his face look extremely creepy and his eyes gleam in a really disturbing way).
Do you think that might be a good way to go about lighting/shooting it? (By the way, sorry for the long post and the abundant use of parentheses).



