Production Lighting: How To Light Car Interiors
With production lighting, certain productions may require you to light a car interior. Whether the scene takes place at night or during the day, this will require some technique.
Step 1: Lighting during the Day
If your scene takes place during the day, you will probably be able to achieve exposure inside the car. This may not be true if you have tinted windows, but generally, you should be fine. However, you run into problems when you start looking out the windows at the outside world. Everything outside the car will be blown out when you expose the interiors correctly. You may be able to coat the visible window with ND gel. This will bring down the exposure of the exterior, but will also cut down any light entering through that window. Note that ND gel is very difficult to make completely smooth so it may end up being more trouble than it is worth.
Step 2: Reducing Contrast
Since lowering the exposure of the exterior may prove to be unfeasible, you can now consider increasing the exposure inside the car. If you are going to attempt this with lights, you will need some strong daylight balanced lights. Try shooting some HMIs through the windows you are not seeing. With some diffusion, the light quality can be quite nice. You can also try to use daylight balanced Kino Flos inside the car. Though this can get a bit crowded and difficult to control, you can easily run this small unit off of an inverter plugged into the car's cigarette lighter. Finally, you can attempt to harness the sunlight with a shiny board. This causes a very intense, very hard light source which should only be used as a back light so you do not blind your actors.
Step 3: Lighting at Night
Night time will not have the same contrast issues as day time. However, you will need to expose the scene. You can attempt to light it from the outside much as you did with the day set up. The trick is getting the light to look natural. If you can motivate street lamps, this should not be a problem. If you are only using moonlight as a source, you will need to use some finesse. You can also use the Kino Flo technique inside the car. A very gentle glow from the dashboard is completely feasible. If you go too intense with the interior lights, the car will begin to look like a space ship.
Step 4: Movement
If your car needs to be moving during the shot, you will need to have all your light sources moving with it. This will not be a problem for any lights inside the car powered off of an inverter. However, for any lights outside the car, you will need a trailer to attach them to. This is usually very expensive so you may need to avoid such sources all together. For night scenes, you may be able to keep the car stationary and create an illusion of movement with some moving lights. You will have to compromise by only seeing black out the window, but the effect will sell.
Car interiors can be tricky to light realistically. Subtlty is the key.