DMX Controllers
DMX, which stands for Digital Multiplex, is a digital communication network used to control stage lighting and effects. Most systems have a combination of lighting instruments, all controlled by a single console known as a DMX controller. It connects to the first fixture in the chain using a DMX cable, with each instrument then “daisy-chained” to the next, and so on, throughout the chain.
The DMX controller provides control of the intensity, color and movement of every fixture in the chain. It can also be used to blend colors, fade lights in and out or even time the strobes to the tempo of a track, depending on the system.
Wireless DMX is becoming extremely popular with inexpensive units now available. They’re reliable and eliminate long DMX cable runs.
Programming Scenes
Now that you’ve got the proper coverage and understand how to use the controller, it’s time to program “scenes,” which are preset looks you can toggle between and adjust from song to song. Scenes include:
Monochromatic. One color, but most people like to use different shades. Granted, these looks can be a bit boring, but they work well for setting the stage, opening bands, or songs with colors in the title.
Complementary Colors. Two colors that complement each other. These looks work well in most situations. Common examples include red/green, blue/yellow, amber/magenta and cyan/amber.
Triads. Although it’s harder to pull off, you can use three different colors in a scene. Pick colors that create a triangle on the color wheel. The most common options are red/green/blue and cyan/magenta/yellow.
Adjacent Colors. Similar to monochromatic, you can create scenes with adjacent colors on the color wheel. Pulling this off typically involves the use custom colors, but it can create a cool faded look.
Color Temp. Similar to adjacent colors, you can create looks using three colors of the same “temperature.” For instance, use three “warm” colors like red, orange and yellow, or three “cool” colors like magenta, blue and cyan.
Defining Terminology
Key terms used to describe the quality and characteristics of lights are throw, beam angle, field, field angle, spill and temperature.
Throw is the distance between the front of a lighting fixture and the object or person that the light shines upon. Just as sound waves follow the inverse-square law, so do lights – a doubling of throw distance reduces the illumination on the subject matter to one-quarter of the intensity.
Beam angle is the shape or angle of the cone of light that emanated from the front of a fixture. Most modern lights express the angle in degrees. A 19-degree beam projects a smaller circle of light on stage than a 36-degree beam angle and can throw a bit farther for the same wattage because the light is concentrated in a tighter pattern.
Field refers to how the light intensity is spread across the beam. A unit that produces a “hot spot” in the center of the beam has a peak field, and a beam that has even light intensity had a flat field.
Meanwhile, field angle is the beam that emanates from the fixture when it reaches 10 percent of the light intensity at the center of the beam. Spill is the unwanted light on stage, either from venue sources or leaked from stage lighting.
Temperature refers to the “warmth” or “coolness” of colors. A higher color temperature will appear “colder” and more toward the white and blue side of the scale than a lower color temperature, which will appear “warmer” or more toward the red side of the scale. This measurement is stated in Kelvin (K). Standard incandescent lamps are about 2800 degrees K (they appear orange to our eye compared to daylight) and tungsten halogen lamps (common in stage lighting) are in the 3200-degree K range. (Daylight is approximately 5600 degrees K.)
Final Notes
While the human eye and brain are good at color correcting, cameras are not. Light sources need to be balanced in the same color range when doing film or video or else objects and people on camera will appear to change hues as the different lighting sources illuminate them. Color correction filters can be placed in front of lights to balance the sources. Other filters called gels can be used to color the light beams.
Another light fixture variation is open faced and lens. Open face units basically simply contain the lamp in a reflector and direct the light out the open front of the fixture. These are useful in washing a large area with light. A lensed unit offers more control of the light and can focus the beam. Some of the newer units allow remote control of features like dimming and color selection, and they allow the operator to concentrate on just aiming the fixture.
The key to stage lighting is anticipation. Operators must be able to anticipate what the music is going to do, and they should be able to count eight bars in their sleep, in addition to being able to feel changes in the music before they happen.
This is because lights should change in time with the music. The biggest changes should come on the downbeats, and when the song changes parts (verse, chorus, bridge, etc.). As the song becomes more exciting, the lights should become more exciting too. That means more changes, and more movement.
Feel the music and listen to the lyrics of the song. Try to enhance what the singer is saying. Try to capture the mood and the vibe of the song with the lighting.
The sound is important – without it there would be nothing to listen to. But the lighting can be what separates a good production from a great one.