In our first 3 Lighting 101 articles, we dove into the less glamorous topics of DMX, lighting control and dimming. While these maybe aren't the coolest parts of your lighting system, they are the most critical if you want any control over how much light your fixtures put out. But, now that we've got the basics of lighting infrastructure covered, let's dive into the more fun aspect of lighting: fixtures! This week we're going to look at conventional lighting fixtures, meaning fixtures that use a conventional-styled lamp. They require more power than LED lights and must be controlled with a dimmer of some kind as described in our last article.
Parabolic aluminized reflector fixtures, or PAR for short, have probably been the most widely used fixture in theatrical and concert lighting over the years. PAR fixtures, often referred to as PAR cans, are essentially metal hoods which hold sealed beam lamps, very much like old school car headlights. They produce a circular or oval, soft edged pool of light, using various types of lamps that produce the different beam sizes and shapes. ETC Source 4 PAR fixtures are the exception to this as they have separated the lamp and lens to make your beam shaping interchangeable separate from the lamp. PAR fixtures are one of the most cost efficient lighting fixtures in terms of functionality with few features such as focus or shuttering. It is a pretty simple point and shoot fixture, providing a fairly even beam of light with softer edges. In conventional lighting settings, I highly recommend PAR fixtures anywhere a softer white or colored light wash is needed.
Ellipsoidal Fixtures are generally fixed-beam sized spotlights that produce a round, focusable beam of light. The ellipsoidal shaped reflector establish the various focal lengths, with smaller barrels being used to provide a wider coverage and larger, longer barrels used to provide tighter coverage. In addition to being relatively focusable, this type of fixture incorporates the use of shutters that can shape the beam of light or cut off any over throw onto unwanted surfaces. Ellipsoidal fixtures can also be used for pattern or gobo projection. ellipsoidal fixtures allow you to light people strategically without washing out up stage walls and/or lighted sets.
Border/Strip Lighting Fixtures
Border/Strip lights have two main functions: to light up large surfaces evenly and to provide discrete front light from below. A strip light is a multi-lamp fixture, normally wired in 3 or 4 circuits and free standing on the floor. In venues with live video, especially HD video, strip/border lights can provide and effective up light to help distinguish details on people and because they are fairly low profile, they sit low to the ground. When used to light large surfaces with color, they'll generally use glass color filters called roundels as opposed to gels. Cyc Lights are the modern improvement of the strip light for lighting large surfaces such as a wall or cyc (short for Cyclorama). The cyc light has a special shaped reflector, which produces a smooth field of light from top to bottom of the surface. Cyc lights are available in one, two, three or four "cell" units designed to be installed overhead or free standing on the stage floor.
Fresnel fixtures provide a high power, soft-edged beam of light. With a variable focus from "Spot" to "Flood", fresnel fixtures are often found in video studio environments because of the very bright, extremely smooth and even light they provide. You'll also often see fresnel fixtures on stages where video, maybe for TV production, has a high value. Fresnel fixtures can produce a nicer, more even light than PAR fixtures but tend to be less energy efficient.
As we wrap up our discussion on the most commonly used conventional lighting fixtures, we want to again point out that all of these fixtures require dimmable power fed to them if you want to control their intensity. Now, what fixtures are right for you? As with most things tech, the answer is, "it depends on what you are trying to accomplish." If a critical component of a ministry is video (such as multi-site churches), we may look at incorporating more PAR or fresnel fixtures for front, side and top light. As for top/back light, we generally stick with PAR style fixtures, regardless of whether they are conventional or LED PAR style fixtures.