How to Use Incandescent Light in Your Digital Film
Sunlight is the ultimate form of light for DSLR filmmaking. It's also the ultimate incandescent light source, or source that produces light by heat. Although its actual color temperature varies widely depending on its position and atmospheric conditions, it still produces a full spectrum of color. That means you can adjust the color balance of the scene to eliminate a colorcast.
While sunlight is the big kahuna, it’s not the only light produced by heat. Here are a few more to consider. Ever touch a light bulb or light a match? Oh, yeah.
Film with candlelight
While candlepower worked for the Flintstones, it’s merely a metaphor here for the basic form of incandescent light, and by default, the warmest type. In fact, all light sources are rated in footcandles. On the Kelvin scale, it’s sub-2,000K. The good part about it is that warm light never seems to get old, instilling a warm and cozy feeling in our hearts and ultimately the viewer.
If for some reason you choose to go Flintstones on your movie with a candlelight scene, take this into consideration:
Be careful. It is fire and it can burn.
Use the light as the subject. For a table scene, measure the exposure from the candle and don’t worry too much if the subject is a bit underexposed.
Find strength in numbers. A single candle isn’t usually enough, but a group of them becomes a force to reckon with. Use a candelabra or multiple candleholders for soft, warm illumination.
Film with tungsten illumination
Tungsten lighting produces light by heating the metal tungsten filament inside the bulb until it glows. In a sense, each bulb operates as a miniature sun. This form of illumination covers a wide swath of incandescent lighting types that produce a light temperature ranging from a household bulb at 2,800K to standard location lighting at 3,200K.
Film with household bulbs
Just about every room in your house or apartment has a bulb, making it possible lighting for your movie. These bulbs' effectiveness, however, depend on several factors, including wattage, placement, and positioning. Brightness ranges from the 25-watt bulb in your refrigerator, to the 75-watt bulb in your lamp, on up to a 100-watt recessed light. Outdoor spot and flood lighting can even give you 150 watts.
Household bulbs can provide a fair amount of light, but they're not always positioned for a flattering effect. Of course, with some strategic maneuvering, they can work well to illuminate some of your interior scenes.
Here’s what you do to take advantage of it:
Take a white balance. Household bulbs produce a color temperature of 2,800K, making them slightly warmer in appearance than tungsten.
Remember that its light falls quickly. Although you can get great illumination from room lighting, keep in mind that it’s relatively low in intensity and exposure changes when the subject takes even one step away from the light source.
Watch out for hot spots. Although household lighting isn't incredibly bright, it's still relatively bright. If you include the light source in the scene, be careful it doesn’t reproduce a bright spot in the scene or flare into the lens.