Compared to saltwater/brine dimmers, and even purely conventional lighting systems, moving light technology is still very much in its infancy. It's just under 20 years since the inception of moving lights, and probably less than 12 years since moving lights really revolutionized the lighting industry.
Within those 20 years, the demand for someone who could manipulate, control, and record all of the complexities and characteristics of moving lights grew faster than the technology itself. Lighting designers needed a person who could program these fantastic instruments at a very rapid pace, someone who could present all of the capabilities of the fixtures and the desks as well as produce the designer's vision almost telepathically. As a result, a new lighting position, the moving light programmer, was born.
Two factors--lack of equipment availability and public information about moving light programming and the various techniques programmers use--have often made it difficult to learn the basics of this craft. The quantum leap of changes to protocols, consoles, and the lights themselves have also contributed to the ever-increasing list of things you must know and learn to be a successful moving light programmer.
Within the last 10 years, a pattern has emerged in the industry of how programmers go about programming moving lights. The following is part one of a two-part article outlining this pattern and a discussion of the basic tools and skills used in this craft. Most of what is discussed here is non-specific to any one fixture or desk, just as music theory is non-specific to any one musical instrument. Learning the common thread that each of these fixtures and desks share is the key to understanding them all. Although it might take some practice developing your chops on any one desk or set of fixtures, if you have a good foundation of the theory behind them, you'll find that learning the specifics will come much more easily and naturally. My intention is to give the reader an overview of basic programming skills and knowledge as well as a good foundation that can be applied globally to the ever-growing list of consoles and moving lights.
To fully understand the organics and biology of a human being, you must first break it down to its simplest form, the single cell. The same concept applies to understanding the mechanics behind moving light programming. The simplest form of moving light programming is the parameter. A parameter consists of any function of a light that can be controlled via your console. New parameters are constantly being added to moving lights, as are different modes that add or subtract parameters or functionality to existing parameters.
When a new light comes out, there's usually a great amount of publicity on its initial release. You can easily find out what its parameters and capabilities are by accessing that particular manufacturer's website and downloading the parameter sheet. This sheet will usually outline what channel corresponds to what parameter, and what ranges govern each characteristic of that parameter.
Many lights start out with one parameter set, and within a few months an adjustment to the firmware has been made that will allow you to have 16-bit pan and tilt, separate control over the gobo wheel parameter and its rotation parameter, or a variety of other changes. Some lights already have these different parameter configurations upon their initial release. These different parameter configurations are known as modes, and are usually modified by setting the light's personality via its dipswitches or menu platform, and sometimes upgrading the firmware within the light itself. When telling the desk what kind of fixture you will be working with, you will often come across several different versions of the same light, the only difference being the mode of operation you wish to work with. If you don't know which mode is most suitable to your individual needs, you won't be able to benefit from either the extra control of the instrument or the conservation of DMX channels.
In the dawn of time (well, roughly 20 years ago) the only parameters that existed were Intensity, Focus, Color, and Beam; abbreviated as IFCB, these are the parameter groups. IFCB is a way to organize and manage all of the parameters into four unique groups. Every parameter in a light falls into one of these categories.
Intensity (parameter group I) controls the light output of the light. There are many different types of mechanisms that control the output level of a fixture; some fixtures have variable metal gates that interrupt the beam path, others have iris-type mechanisms that close or open in order to control intensity. These mechanisms open and close dynamically relative to the output level you specify. You can change the speed of the intensity fade by altering the time of the cue that it's recorded in. Intensity also includes the control over conventional dimmers.
There are many cool effects you can create by using intensity. From subtle to staccato, you can chase intensities in symmetrical or random design to create a crossfading subtle effect or an energetic stroboscopic effect. In some consoles, you can give every light's intensity levels different fade times, delay times, and cue profiles.
The decision whether or not to record intensity levels for a cue as a palette is yours. In the case of film or TV, it might be useful in adjusting a show's output level per camera angle of F-stop. I generally don't store intensity as a preset first because I like to be able to see and adjust the intensity on the fly.
Pan and tilt (parameter group F) revolutionized the lighting industry by giving lights the ability to move. Movement as an effect can draw focus or create an environment that is conducive to what's happening onstage. Movement can also reduce the number of channels and dimmers allocated for conventional lighting; you can also use the movement of the fixture to fade out, move to another position, and then fade up as if you were moving from one group of conventional lights to another. This technique is known as presetting, or marking, and is widely used in theatrical applications as well as rock and roll.
Pan and tilt can consume up to four channels (two each) for 16-bit fine resolution or two channels (one channel for each) for eight-bit resolution. The differences between 16-bit and eight-bit pan/tilt resolution can be negligible at faster movement speeds; it's when the light is moving slowly that you can see the difference.
In 16-bit mode, one of the pan or tilt channels controls the low, or coarse, bit of resolution while the other controls the high, or fine, bit of resolution, giving you a much smoother degree of pan-and-tilt movement. In eight-bit mode, pan and tilt are allocated only one channel apiece. This doesn't necessarily mean that you're going to have a noticeable defect in your pan-and-tilt moves; there are a few fixtures out there that actually move more smoothly at slow speeds.
Pan-and-tilt levels are almost always stored in your focus palette before using those levels in a cue. There are a wide variety of types of focuses you should keep at hand in your focus library before starting the cue-building process.
The cornerstone of design, color (parameter group C), lends us its power to express the mood of the scene or to add dimension to what we are lighting. Moving lights and color add a whole new dimension to the process. The ability of a moving light to change from one color to another over the course of a split second or several seconds facilitates the changing of the mood of a scene with the same set of lights.
The majority of color filters used in moving lights are dichroic. A dichroic filter differs greatly from that of its predecessor (gel) in that instead of absorbing unwanted wavelengths of light as heat, it reflects them back into the reflector. This gives dichroic filters an incredible lifespan and ensures that only the desired wavelengths of light required to produce a desired color will pass through the filter.
There are a wide variety of mechanics involved in how color is output from a moving light, but they can be broken down into two distinct groups: color wheels and color mixing. Some lights have both; some have one, two, or even three color wheels.
A color wheel is a wheel with many slots of color in it. The slots usually start at white when outputting a zero-color wheel percentage, and will move to the next color as the level is adjusted higher on the desk. On some lights, it's possible to fade from one color to another over the course of time, or to snap immediately to the next color.
The advantages of a color wheel are: the color it produces when the filter is fully engaged is solid and pure; and it creates a very even field within the beam of light. You won't see any discrepancy of color in the beam, or the surface it's projecting on, unless the dichroics are burned. A disadvantage of a color wheel is not being able to smoothly crossfade to any other color on the wheel except for the color on either side of the color you're in. Invariably, you will pass through a contrasting, possibly undesirable, color to get to the desired color on the wheel. In some instances, this may be a desired effect. One way of getting around this is to fade the light out first, preset the light in the color you desire, then fade the light back up.
Colors in a color wheel should always be recorded in palettes before they are used in cues. When recording a color palette using a color wheel, make sure you record each palette in the order it is on the wheel (i.e., color one, palette one; color two, palette two). Recording your palettes in such a fashion facilitates ease and speed of being able to tell the designer exactly what color is next to the current one and how many colors reside between the current color and the one requested. This is a very important palette-building technique and should be applied to color, gobo, and FX wheels alike.
Color mixing (parameter group C) uses at least three parameters, cyan, magenta, and yellow, the three subtractive color primaries. A combination of any two out of three of these parameters, fully engaged to interrupt the beam path, will yield the subtractive color mixing system's secondary colors Red (fire), Blue (congo), and Green (or pretty close to them). Varying degrees of combinations yield different hues as well as saturation levels of color. Nearly all color-mixing lights employ the subtractive color-mixing system, which I will explain in more detail in the second part of this article.
The beauty of color mixing is that it gives you the complete flexibility to create a very large color palette and crossfade from one color to another over the course of time, without a noticeable flicker that you would get from a wheel. At least, that's how it's intended to work. Not all color-mixing systems are the same; they come in a wide variety, and some are more efficient than others at producing certain colors, as well crossfading from one color to another.
There are some disadvantages to color-mixing systems--for instance, the vast majority are unable to produce a true red. Instead, a combination of the yellow and magenta color parameters will yield either a very saturated amber or a fire red, which falls more on the amber side, which means you have to revert to the color wheel for a real red. With the majority of color-mixing systems, a perfectly flat field in your beam is nearly impossible to achieve when mixing more of the pastel or less saturated colors. You usually end up with a beam with slight blotches or patches of the color you are trying to mix.
A color-mixing palette's organization is very important and will aid greatly in the speed in which it takes you to access a desired color.
Gobo wheels (parameter group B) present you with the option of adding a variety of textures to a picture. Texture can be defined either as projected surface texture or aerial texture. Surface texture is the result of the gobo pattern projected on a surface and can be razor-sharp in its definition, or very soft, to make subtle blendable textures. Using more than one gobo wheel overlapping the other and rotating it can enhance surface texture and create a wide range of looks.
Gobo wheels currently come in two varieties, standard (static) or rotating. The mechanism is nearly identical to a color wheel in shape, but differs with the rotating sort. In a gobo wheel, you have an open slot and several slots of patterns thereafter. The slots will change with the changing of value sent to the parameter, and it's possible to have split gobos. Some gobo wheels have the capability to vibrate very quickly, producing what is known as a gobo shake.
Rotating gobos will move in either direction or index to a specified angle, depending on the range you specify in the parameter (and also depending on a fixture's capabilities). When indexing all of a light's gobos, turn the gobo clockwise or counter-clockwise until you find the desired angle, then record the value, either in a palette or directly into the cue. With the ability to index gobos, you can do things like lining up all of your multibar gobos across a range of fixtures so they're all pointing up to downstage, or stage right to stage left. You can create perfectly uniform gobo washes or angle a selection of a fixture's gobos to wash an angled set piece exactly the way you want it. Bear in mind that not all fixtures with a rotating gobo are able to index.
The part of the parameter that controls the rate of rotation sometimes resides on the same parameter as the rotating gobo wheel and changes speed/direction depending on the value of output given to the parameter. There are many instances in which the rotational rate and indexing angle are stored in an entirely different parameter, which we will refer to as gobo rotation speed. Both wheels should be recorded as two separate rows of palettes in the order that they reside on the wheel, each containing values exclusive to that wheel, so you can overlap them at will.
Gobo rotation speed (parameter group B) controls the rate that a gobo will spin, and in some cases will give you control over the way a gobo is indexed. Gobo rotation speed can also affect the direction your gobo rotates. This also depends on the manufacturer of the fixture.
You will not always find a separate rotation channel for a fixture. Sometimes the gobo rotation speed resides in ranges on the rotating gobo channel. Sometimes a fixture will have the added functionality of a separate rotation channel just by changing the mode the fixture is in.
It would be wise to record many different ranges of this parameter in your beam palette. The ranges should always include a stop spin range: slow spin, medium, fast, etc. You might want to have more varying degrees of slow gobo rotation speed rather than fast. It'sbeen my experience that designers want a larger degree of slow to medium ranges of gobo rotation speed than medium to fast.
FX wheels (parameter group B) are similar to gobo wheels, with one exception: instead of gobos in the wheel, there are several effects to use in conjunction with the gobos. Some common effects are doubling, tripling, quadrupling, and quintupling prisms, as well as hazing and tracer prisms. Other common effects employ the use of multiple color dichroics that usually split the beam into two or more colors. All of these effects have the ability to rotate and index depending on the limitations of the fixture itself.
The same principle applies to the palletizing of FX wheels as it does to gobo wheels: Record them in slot order. If a fixture has more than one effects wheel, you should palletize that wheel in different palettes than the other, again allowing for a greater flexibility when overlapping the two.
The iris (parameter group B) of a light adjusts the beam size and varies dynamically, depending on the level output. This gives you the flexibility of creating a variety of different beam sizes. Bear in mind that when you close the iris to adjust the beam of a fixture, it will truncate the edge of any other parameter in the beam path. If you want all of your beams to be smaller without affecting the edges of the gobos, you should use the zoom parameter instead of the iris (if the light is equipped with zoom) to adjust the size of the gobo.
When chasing irises in a system from open to closed, an undulating effect is created. There are many ways to create interesting looks by chasing irises in conjunction with another parameter, such as intensity. One such example is when all of the irises and intensities are closed and you randomly bump open both parameters in random groups of four or more depending on your system size. You should at least have an "iris open" and an "iris closed" at hand in your palette library.
Lens focus (parameter group B) controls the varying degrees of beam sharpness. Focus gives you the ability to control how soft or sharp you want the gobos or any other focusable parameter to be. With lens focus, you can tune gobos to razor-sharp definition or rack them out of focus for a less literal, subtler texture. In an instrument with two gobo wheels that have distinctly different focal lengths between them, you can use lens focus to morph from one gobo to the other if they share similar light-passing characteristics.
Lens focus is preferred both sharp and soft by most designers, so it would be wise to include a couple of degrees of lens focus in the beam palette. Bear in mind that if your fixtures have both zoom and lens focus, one will always affect the other and you should either include them in the same beam palette or not, depending on your circumstance.
Zoom (parameter group B) controls the overall size of your beam and every other parameter in the beam path. Zoom doesn't affect the edges of a gobo; instead, it will resize the entire gobo or whatever other parameter might be in the beam path. With zoom, you may not be able to achieve as tight a beam as with an iris, but zoom's function isn't really to resize the beam itself; its primary function is to resize what you are projecting on the surface you are projecting it on. Zoom also comes in two flavors, variable and wheel.
In most lights, it is impossible to use zoom at its extremes while keeping the lens focus crisp. In other words, you won't be able to keep your gobos or other textural parameters sharp when zooming all the way in or out. This may be a desired effect in instances where you are using gobos out of focus to add subtle texture.
It's a good idea to record a couple of palettes with different zoom sizes, so you will be able to quickly change the aspect ratio of the light's projected beam size. You may also want to store zoom along with the gobo wheel to ensure it will always come back to the base size, if that's what you desire. Keep in mind that changing the zoom will also affect the lens focus, and both should be adjusted proportionally.
Frost, or diffusion (parameter group B), will turn your hard-edge fixture into a wash fixture by softening the beam, or will give a wash fixture a wider beam angle, enhancing the widest possible area coverage.
Frost is similar to zoom in that it too comes in variable or wheel form. With wheel frost, depending on the fixture, you can make slow changes from one slot to another without a noticeable flicker caused by the area in between the two slots.
Strobe (parameter group B) is one of the more erratic beam parameters. The strobe parameter of a light is controlled by a swiftly moving gate that interrupts the beam path to allow light to escape the fixture in either an on or off state.
Unlike intensity, strobe is only variable in the speed and style (simultaneous or random) at which you want the light to turn on and off. There are strobe wheels with one slot that continuously spins to achieve this effect, and in some cases the strobe channel uses the same gates allocated for intensity to create the stroboscopic effect. Strobe's default is open, and from there you will go through many stages of strobing rates, simultaneously or randomly strobing on and off.
Blade (parameter group B) employs the use of the same technology used to shutter a leko off to a given area. Blade uses up to nine parameters: two are for each end of one of the four blades, and one is used to rotate the entire blade mechanism. Currently, there are only two major fixtures which employ this technology, the Martin Pal 1200 and the Vari*Lite(R) VL7B(TM).
There are several different strategies you can use when recording shape into the palettes. The first is to record the shutter shape into the beam palette and label it in correspondence to the position focus you shaped it to. The second, provided your console supports it, is to record the beam information right into your position focus palette along with the pan-and-tilt values used; after all, when you're focusing a leko, part of that focus is the shutter or blade mechanism of the light itself.
Speed (parameter group B) is a peculiar parameter, in that it usually determines the time at which a gobo or color wheel will traverse to the chosen gobo or color. Speed also determines the speed at which the mirror travels. The speed you specify is usually cumulative to the time already specified in the cue fade time, which can become quite confusing. In some fixtures, this is the only way to roll a gobo or color to another on the wheel, so you must use speed in order to achieve the desired effect.
I've found that if you need to use speed to roll a gobo, it's best to put a zero-second time on those parameters that speed governs. This will allow you to make all of your parameters that are moving from cue to move with one time.
The control parameter (parameter group B) allows you to remotely reset or home the light as well as douse or turn on the lamp, depending on what range the parameter is set to. Some lights don't have a separate channel for this and these functions either are unavailable or reside on the strobe channel.
Operators and technicians often ask to have these different states of the control channel prerecorded into the palette library for quick access. It's highly recommended that you do this if the console allows, in case a fixture starts acting up in the middle of a show and you don't want to take the time to manually access this parameter and adjust or reset it.
In this point, we've discussed moving light parameters and their functionality, as well as what parameter groups they fall into, and a couple of basic palette-building strategies as well. These parameters are the building blocks for palettes, just as palettes are the building blocks for cues. It's imperative that you move with technology and keep an eye out for new parameters and new lights, as this will greatly improve not only your knowledge of the lights themselves, but also your power to create new and beautiful looks.
Part two of this article, covering palettes, presets, and libraries, will appear in the October issue of Entertainment Design.>ENmeter group B), will tu