Sometimes we're too busy illuminating you in this department to define basic terms, like, for instance, all the different lights we talk about. So here's a quick description of the movie lights commonly used for video. Seat belts please; we're gonna move fast.
But first, three terms that apply to all lights, irrespective of type or purpose:
BTW: a "bulb" is something that grows into a tulip; it is not a proper synonym for lamp.
Okay, the three main types of movie lights are spotlights, floodlights, and softlights.
Spotlights
Spotlights are small-source instruments, meaning that the lamp and reflector are rarely bigger than six inches across (though film studio spots can be waaay bigger). All but the cheapest models can be focused, narrowing or widening the light beam by moving the lamp forward or back in its housing.
Because of their small light source and their ability to focus, spotlights throw a relatively directional and "hard-edged" beam, meaning that its intensity falls off very quickly at the perimeter. (Ellipsoidal spotlights and beam projectors have even harder beams but are usually exclusive to clubs and theaters.) You can control spotlight beams precisely by masking their edges with barn doors (movable flaps mounted on the instrument) and flags (opaque boards held in the beam on stands). Nowadays, all spotlights use special halogen lamps.
Larger, heavier spotlights are supplied with Fresnel lenses (pronounced "fruh-NELL" and capitalized for M. Fresnel, their inventor). These distinctive concentric-ringed lenses make the light even more directional and hard-edged. Small, light-weight spotlights intended for location lighting often sport a simple diffusion lens instead, or else no lens at all.
Tiny 12-volt spotlights can be camera-mounted. Versatile models have multiple heads and lamps, for varied lighting intensities and beam-spread; and they can be fitted with barn doors, filters, and even Munchkin softboxes. Used alone, on-camera spots can produce crude-looking lighting; but they can be invaluable supplements to stand-mounted units.
Because you can soften spotlights (see below) they are the most versatile lighting instruments, suitable for key, fill, rim, and background illumination. However, learning to control them takes practice, so spotlights are harder for the casual user to manage.
Floodlights
Because floods are larger light sources than spots, they have the opposite virtues and vices. Lacking lenses and focus systems, they are simple and less expensive; and their soft-edged light beams take little practice to manage. On the down side, they are difficult or plain impossible to mask, spilling their beams all over the place.
The smallest floodlights are broads: shallow rectangular pans usually fitted with two narrow barn doors. Used naked, they can throw effective washes on walls and other backgrounds, but because they are still relatively small, they often need extra softening, usually with sheets of white spun glass held in front of them on frames.
Scoops work much like broads, with big, open reflectors in circular housings. Because of their size, weight, and bulk, the bulk of their use is for studio work.
Pans are very large lights (some over four feet square) that throw ultra-soft even light beams that seem to wrap around subjects. Pans contain several high-accuracy fluorescent tubes, and some models allow you to switch them individually. Pans are fairly clumsy to use; but vendors have added conveniences like bodies that clam-shell shut to form their own cases and fluorescent ballast units that function as counter weights. Typically balanced for daylight, pans work well with location windows and existing fluorescent ceiling lights. Like all, fluorescents, they are more efficient than lights with halogen lamps, putting out substantially more light (and less heat) per watt of power.
Softlights
Pans bridge the gap between floodlights and softlights. Softlights are very large lights sources (typically 1 ½ to 4 feet square) created by placing the instrument inside a fabric enclosure or else aiming it at a reflective umbrella. All softlights deliver a diffuse beam that is easy to use and looks very natural. On the down side, you can't control the edges of softlight beams (though some types include accessories to limit the beam spread).
Some soft lights are really accessories for small spotlights, which mount at the rear of a fabric cube with opaque sides and translucent front. Other versions are "pure" softlights, with open lamp-and-socket assemblies designed for specific housings. PhotoFlex, for example has a proprietary tent engineered like an umbrella.
Actual umbrellas have been used as softlights for decades. Mounted on a stand, the umbrella reflects light onto the subject from a small spotlight clamped to the bottom of its "handle" and aimed into the fabric bowl. Umbrellas are versatile, inexpensive, and easy to carry and store. You can get different levels of diffusion by using different fabrics — say, silver-thread cloth or plain white. For a super-duper soft effect, fit a translucent white umbrella and reverse the unit so that the spot aims at the subject through the diffusing cloth.
Lamps
Nowadays, almost all professional lights use either halogen or fluorescent lamps. Halogen lamps are small and very bright for their power consumption. They burn at precisely 3,200K color temperature, for perfect indoor white balance, and unlike household light bulbs (yes, bulbs) they don't dim and yellow as they age.
On the down side, halogen lamps get so hot that their envelopes must be made of quartz, rather than conventional glass. Touching them causes serious burns; and even when the lamps are cold, human fingers leave skin oil deposits that will make the quartz shatter spectacularly when heated.
Fluorescent lamps now come in all shapes and sizes. In addition to the traditional tubes, special compact designs can fit into proprietary softlights. Recently, curly fluorescents no bigger than household light bulbs have been introduced, with clean 5,000K color temperature and standard medium screw bases. The biggest now available deliver the light of a 150 watt incandescent.
And they do it on 25 watts or less, because all fluorescent lamps deliver substantially more light per watt than incandescents do, and they never get hot enough to burn flesh — an important consideration in school classrooms. With an all-fluorescent light kit, you can light, say, an interview with three lights, all on a single 15-amp circuit.
When you buy conventional fluorescent tubes, be sure to get the "high accuracy" type for good color temperature. At most store displays, laminated cards carry the relevant information about every type of tube sold.
Hardware Store Lights
By now, most people know that stand-mounted halogen work lights from X-Mart or Builders Depot work very well as movie lights. But don't forget about screw-base household halogen lamps as well. Reflector types (outdoor security floodlights) work fine in plain sockets and bulb-type halogens can be fitted in light-weight clamp-on reflector work lights.
Halogen lamps are also useful in "practicals," regular lamps and fixtures that will be visible in the picture. That's because they are brighter than household bulbs, and burn at the proper movie light color temperature of 3,200K, rather than at the more yellow 2,700-2,800K of ordinary lamps.
Good shooting!
Contributing Editor Jim Stinson is the author of the book Video Communication and Production.
