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ALTMAN 65Q FRESNEL
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ELATION PROFESSIONAL DESIGN SPOT PRO 300 MOVING HEAD SPOT FIXTURE
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ADJ PAR-46B
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CHAUVET Q-WASH 560Z-LED MOVING HEAD WASH FIXTURE
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STRAND LIGHTING LEKO LITE
Theatrical lighting fixtures are the lighting designer's paintbrushes. The lighting designer chooses his fixtures carefully, because every fixture type has different capabilities and can create different qualities of light. Only through a great deal of research and actual experience can a lighting designer know what fixture to use for each purpose.
Quick review by type
First, a quick review of the different kinds of lighting fixtures is in order. There are “conventional lighting fixtures,” which include Lekos, Fresnels, PAR cans, strip lights, and other fixed lighting devices. Conventional, or fixed, lighting fixtures are usually the most affordable tools available to the designer.
Automated lighting fixtures, or “moving lights,” offer the designer greater flexibility in focus, texture, and color change. There is a wide range of automated lights including moving heads, scanners, and automated accessories that you can attach to conventional fixtures. Sophisticated lighting control desks control these lights remotely.
Ellipsoidal reflector spotlights (Lekos) are the most common conventional lighting fixture in the theatre. They are designed to be able to control the shape of the light through the use of shutters. In addition, you can place a pattern, or gobo, in the light and project it onto the stage. This is possible because the design of the Leko directs the light rays to a second focal point near the “gate” of the fixture. This is where the shutters and gobo slot are located. The Leko projects the image at this point onto the stage, creating a highly controlled field of light.
There are many types of Lekos available. Most are defined by their lighting spreads in degrees. So a 19-degree Leko has a spread of 19 degrees, etc. There are also zoom Lekos available with variable beam and field spreads; Lekos are the true workhorses of the theatre.
Fresnels are lighting fixtures that are named after the inventor of its lens, Augustin Fresnel. The Fresnel lens was originally designed for lighthouses where the heat of the light source was so intense it would crack a standard, thick, plano convex lens. So Augustin Fresnel designed a lens with much of its glass cut away to absorb less heat, and at the same time keep its optical qualities. A similar design is used in the Fresnel spotlight. This light produces a soft-edged quality of light and is mostly used for soft fill light. Unlike the Leko, a Fresnel cannot project patterns on stage.
PAR cans are the best “bang for the buck”
lighting fixtures. The Par (Parabolic Aluminized Reflector) lamp is a self-contained lamp that has the lamp filament, reflector, and lens all in a sealed beam enclosure. PARs come in several sizes, beam spreads, and wattages. The most common theatrical PARs are the Par 64, 56, and 38. They come in wide flood, medium flood, and narrow spot beam spreads. Wattages vary from 150 to 1000 watts. The PAR produces a very powerful oval beam of light.
The “can” part of the PAR can is the metal enclosure surrounding the PAR lamp. Due to its low-tech design, the PAR can with the PAR lamp is a very affordable lighting fixture.
ETC has designed a new type of PAR called a Source Four PAR. This higher tech fixture has changeable lenses, a dichroic reflector, and a removable and changeable lamp. Although many people classify this as a PAR, it is really a different type of lighting fixture and much more flexible than a conventional PAR can. In addition to conventional tungsten halogen PAR lamps, LED PARs have become very popular. LEDs have the advantage of incorporating multiple colored LEDS, thus allowing color mixing within the light fixture. They also are incredibly energy efficient with extremely long lamp life.
Although Fresnels and PAR cans cannot be shuttered like a Leko, you can attach an accessory called a “Barn Door” to help shape the light and cut it off of masking and walls. There is also an accessory called a “Top Hat” that will reduce the flare off the front of the light. This device can be used in most lights with a gel frame.
Conventional lighting fixtures also include lights that are designed to broadly wash a surface. These include strip lights and cyc lights. Strip lights are fixtures with multiple cells of individual lights ganged into groups of colors. These fixtures are used to light cycs, drops, for footlights, and even for broad washed sidelight. Strip lights come in all shapes and sizes and are usually identified by the lamps they use. The choices in strip lights include PAR strips, MR16 strip lights, and most recently, LED strip lights.
Automated accessories that you can add to conventional fixtures include color scrollers, dichroic color-changers, gobo rotators, scene machines, auto-yokes, and I-Cues. These devices can remotely change color, gobos, project film loops, and can change your static conventional fixture to a modern moving light.
Moving heads & scanners
Speaking of moving lights, technology has evolved to a point where moving lights are pretty common in theatres and worship spaces. Moving lights come in two basic designs, moving heads and scanners. The moving head fixture has a movable yoke that pans and tilts the light. The advantage of this design is that you can point and focus the light in almost any direction. The disadvantage of the moving head fixture is that it is relatively slow due to its large mass and the small, quiet motors required to move it. However, new moving head designs of smaller and lighter fixtures are now being manufactured.
Scanners use a movable mirror to direct the light to its' focus point. The lighting fixture stays in one place and the attached mirror redirects the light. The advantage of this fixture is that it is very fast as the mass of the mirror is small and light. Unfortunately, the disadvantage of this light is that the focus range is limited due to the mirror design. Therefore, great care needs to be taken when deciding how to hang the fixture in order to achieve the required focus range.
Moving lights come in many sizes and models. Moving heads are divided into spot and wash fixtures. Like Lekos, spot fixtures are designed to project the image at the fixture's internal focal point onto the stage. These fixtures can have multiple spinning gobo wheels, effects wheels, irises, and shutters. They also have dichroic color-changers, including color wheels that almost instantly change the color and CMY color modules that can fade from one color to another. Most of these lighting fixtures can zoom their fields in and out to change the size of the beam.
Washes
Like Fresnels, wash fixtures are designed to produce a soft wash of light for blending purposes. Due to their design, they do not have the same features as spot fixtures. However, they are quite useful when powerful colored lighting washes are desired. Unlike spot fixtures, wash fixtures can use LED technology, which makes the fixture lighter, faster and much more energy efficient.
There are also moving lights that are actually video projectors mounted on moving yokes. These sophisticated fixtures can project moving video images that you control through a media server. Although expensive, moving projectors are becoming common tools in video media and lighting design.
Control issues
Conventional and moving lights are controlled by powerful lighting control desks. As is the case with moving lights, technology has brought down the cost of these controllers to a level of affordability for theatres and houses of worship. Today you can purchase a sophisticated moving light control desk for under $6,000. Ten years ago it would cost twice that amount to purchase a controller with only half the features.
Lighting control desks use a control protocol called DMX512 to control moving lights, dimmers, and other accessories. DMX was developed in 1986 by USITT to standardize lighting control protocol among the many manufacturers producing lighting fixtures and control desks. Up until that time, manufacturers were using proprietary protocols that made it impossible to mix lighting fixtures, dimmers, and control desks from different manufacturers. Before DMX, if you used a Vari-Lite lighting fixture, you had to use a Vari-Lite control desk. Now you can control a Vari-Lite fixture with any lighting control desk—no matter who manufacturers it.
So how do you decide which lighting fixture to use without buying every one and trying it out for yourself? Once again, this is where technology comes to the rescue. There are new lighting visualization software tools that allow you to see the lighting fixture in a virtual world. Using software like Capture Polar, ESP Vision or WYSIWYG, you can choose from a huge variety of lighting fixtures in their libraries, “hang” the fixture on a virtual pipe in a virtual theatre, turn it on, and observe how it reacts to your commands. This is especially useful for moving lights, where the choices appear endless.
The other way to audition lighting fixtures and control desks is to attend events like the annual LDI conference, USITT or WFX. These events include showcases of the latest technology in the world of lighting design. On the expo floor you can audition these products with hands-on demonstrations. I attend at least one of these conferences every year to keep up with the latest in lighting technology and learn new technical and design techniques from my professional colleagues.
Learning what fixtures can be part of your lighting palette is an essential step in your development as a lighting designer. Research what is available and try it out in a virtual environment. It may seem to be a daunting task with so many products out there … but the great choices in lighting fixtures and control that are now available to us brings us closer to achieving the lighting atmospheres that we could once only dream about.
