Lighting Key And Systems

TOC - Creating A Rough Plot

We're now at the point in the design process where we need to take your visual imagery, which is just in your head or in some notes, and discretize it, turn it into lighting produced by discrete, real sources of light. We're still not yet worried about the exact type of light you'll need to use, or whether in fact there are any such available; these practicalities will be left for a later stage. Instead, we are just trying to create a lighting key, which is a shorthand for the lighting angles and colors with which the subject will be lit.

• Lighting Key Theory
• Creating Lighting Keys
• Lighting Systems

Lighting Key Theory

The basic idea behind lighting key theory as I use it is that one can take any given lighting scheme, break it into discrete angles and colors, and the duplicate this on a stage. In most circumstances, however, the lighting we are interested in will need to cover far more stage area that a single instrument can cover. What do we do about that? Usually, we break our stage down our stage into areas, and light each area the same way. Actors moving from one area to the other will smoothly transition from one spot to another, and the audience will not notice that they have moved from one set of spotlights to another.

I will discuss the details of creating a lighting key from your visual ideas in the next section, and concentrate here on how this "acting area" stuff works here. An example will make things clear (I hope): imagine that we wish to light a realistic sunlight scene. Clearly, in real sunlight, when someone walks from one spot to another, the angle at which the sun strikes their body doesn't change, because the sun is sufficiently far away that they aren't changing the angle much by moving. In the theater, the light are considerably closer to the actors, and by moving 10' onstage, they may be drastically changing the angle at which the light from the spotlight will be striking their body. If we wish the audience to "believe" that they are walking around in real sunlight (or as close as we can get in the theater, we have a couple choices a) we can remove the roof of the theater, and pray for a cloudless day b) we can try to use lights to achieve the same effect.

Clearly, b) is the one we'll go with, in most circumstances. Let's start by deciding how to light the individual actor, and then later we'll look at how to create the effect of the parallel rays of the sun. Imagine a static scene, where we have our one actor standing alone. Clearly, the sun is providing the most important light in the scene, so we'll start with that. Sunlight is actually a relatively cool light, so we'll point a fairly cool spotlight at the actor (say, plain white). From what angle? Well, we definitely want to see the actors faces, so we'll put it out front. Not directly out front, because we know that that will flatten out the features of the actor. So maybe, say, 30° away from the centerline of the actor, and say maybe 45° from the vertical (this vertical angle is chosen to mimic the angle at which the sun would strike an actor at approximately that time of day, although we've made allowances for making sure the faces are visible).

We've taken care of our key light, but if you look at someone in the full light of day, clearly they aren't only lit by the sun. Their entire body is lit by reflections off of all the surrounding surfaces in various ways. These reflections will be colored and softened by what they bounce off of. This is where careful observations of the real world will be important: go outside on a sunny day, hold up a sheet of white paper, and turn it this way and that and observe the colors that the paper is lit with (you may have to "cup" the paper to mask out strong sources of illumination so you're only seeing weaker sources). Stand next to a brick wall, on grass, next to other strongly colored objects. Look at what happens when the light is filtered through trees, through clouds, etc.

For the purposes of this experiment, we'll say that the next most important light hitting the actor is the light from the sky, which is even cooler than the sun. So we'll place cool-blue gelled spotlights around the actor to achieve this look. We realize quickly that the sky alone would cast a featureless, shadowless light onto the actor from all angles, but we can't really do that onstage as we'll have no control over that kind of light. We can fake it, however, by putting another frontlight on the actor, from the opposite side, and put a toplight over the actors head. These represent the other surfaces of the actor that the audience can see that are hit by "skylight", and if we put a frost in the beams of the spotlight we can soften them so they seem diffuse and without much shadow (if we had lots of lights available, we could put more around the actor, but for this exercise, we won't).

Finally, we'll say that the actor is standing in field of grass, and that this is important for the scene. So we'll provide a little uplight, faintly green, that is caused by the reflection off the grass (the green uplight may be an exaggeration of reality, but we're doing it for a theatrical effect).

OK, so now we have the actor, lit such that if someone were to look at him, out of context, they might say, "OK, there's a guy, standing in sunlight, in a field of grass". But we'll quickly realize that in order to get any control over our lights, we'll have to limit them to a fairly restricted area of the stage, and if the actor starts to move, the angle at which our lighting is striking his body will change and our audience will no longer be convinced. We therefore need to duplicate this look over the entire stage, using acting areas.

We start by breaking the stage up into circular areas that are about 8' in diameter and 6' tall. It turns out that this is a good size, such that we can keep lighting angles fairly consistent but not use too many lights. We then simply replicate our lighting key into each area, so that each area individually is lit realistically. When our actor wanders from area to area, the lights in the next area will "take over" for the lights in the previous area, and the audience won't notice the transition. Clearly, the lights for each area will have to overlap, or else there will be a gap between the two areas. NOTE: I often see designs that overlap neatly at the floor level, but at the level of the actor's head, they have dark spots. Light spreads as it travels, and it is essential to do the design such that the overlap is occurring at the level of the actors' heads, not at the floor (we'll cover this again when we select instruments). This is why our acting areas are 6' tall.

Now, there will be some areas where we can't fully replicate our lighting key because of a lack of lighting positions, interfering set elements, or some other obstacle. In most cases, this shouldn't be too much of a problem, because you can either "cheat" your lights a bit to fit the area, or just ignore it if the area will be little-used. You may need to be a bit inventive about where you can put lighting units, and ways you can get light into tight spaces.

The end result of all this maneuvering should be a smoothly replicated lighting key across the stage. The example I've given, of course, is one of infinite possibilities, and the details of instrument selection and the like have been completely ignored. The intent was just to show why one might want to create and then duplicate lighting keys across multiple areas onstage. The next sections will concentrate on creating the key itself, and then we will discuss the lighting systems thus created.

Creating Lighting Keys

There are really no rules, of course, as to how you should go about creating your lighting keys. The basic idea is to take each scene of your breakdown, which presumably you've done some work to visualize, and then decide how to break down your vision into discrete lighting angles and colors. Clearly, we are ignoring some of the other qualities of light, particularly intensity, distribution, coherence. You will probably have some idea about the relative intensities of the lights you are specifying, but for the most part this is decided when writing cues. Coherence you will deal with when specifying the actual instruments and/or frost gels you will use, and distribution you can decide a bit later when you are more aware of the blocking of the show.

That leaves color and direction, which is really what we're trying to nail down here. You'll be using the same considerations you were using when you did your visualization, and reapplying them based on the slightly more practical considerations of the lighting key. Athough I hesitate to say that you should necessarily limit your design already, you might want to investigate the stage you will be working on and see which lighting angles will simply be impossible. Uplight, for instance, is often very difficult to achive without having visible units downstage, which your director/design staff may not want. Sidelight can also be tough in some spaces. If you discover that certain directions will be absolutely impossible, you should probably avoid using them in your lighting keys.

Start your keys by simply taking each scene, which you should have pretty strong visual ideas about, and think about how to create each "look" with individual lights. There are some formulaic methods to create simple, flexible lighting schemes, such as the McCandless method and a standard sidelight method. Each of these is worth looking at, because they illustrate ways to take visual ideas and turn them into individual lights, although in this case they also focus on flexibility and evenness.

The McCandless method is a good method to create both outdoor and bright indoor lighting, when the lighting is supposed to be fairly naturalistic and even. In general, a pair of frontlights are used, at about 45° off of the centerline and vertical angles. These are gelled with a complementary warm and cool color. Depending on the intensity that you run the lights at, they can suggest strong sunlight with reflected fill, or an evenly lit roomlight. The 45° angle works as a fairly naturalistic angle, one that reveals the face without casting strange shadows. There's usually a toplight as well, which works to even out the frontlight and highlight the edges of the actors such that they stand out from the background. Again, the relative intensities of the three lights can be varied to suggest different environments.

The McCandless method works because it puts lights at the most important angles for creating realistic light. If you look at sunlight, roomlight, etc, you will discover that for the most part people in those environments are usually lit from either 45° vertically or straight from the top (table lamps obviously light from side, back, below, but this would not work onstage unless you actually put a table lamp onstage so the audience had some clue where the light was coming from).

A standard sidelight method is to put up booms at the wings of the theater space, and then put 3-4 lights on each boom, at the shin level, waist level, eye level, and perhaps a higher angle. One might also put lights directly out front. The sidelights aren't terribly realistic, but are intended to strongly highlight the shape of the figures being lit, and reveal the form of that figure. The frontlight is there just to fill in any dark lines, and will be run at a very low intensity. The focus here is on form, not realism, and the sidelight method achieves this by highlighting that which is most important to reveal that form.

I should stress that these formulaic methods are only one solution to the problem, and if you find yourself using them too much, you should seek other ways to achieve the same goals. You will also need to light other kinds of scenes, realistic and not, and make them convincing to the audience. Here is where your knowledge of the emotional effects of angle and color will be very useful. What effect will a deep blue high backlight have? What about a strong white toplight? Red uplight? How will you create the look of someone standing next to a neon sign? Being lit by headlights? All of this should suggest angles and colors that will work, and you should jot this down in the form of a lighting key. You might need to create multiple keys for each scene, if there are different areas of the stage that need to be lit differently, and you might have some scenes that have a single light in their key. The point is just to start to formalize your ideas about color and angle.

To this point, you haven't really been using the tools of the lighting designer, you've just been saying "a light from this angle, with a deep blue gel". But now is the time to start working with one of the most important tools, gels. Get yourself gel swatchbooks for Lee, Rosco, and GamColor gels. Swatchbooks are available free from Alan Symonds and High Output. You will of course have some particular color in your mind, as you start working on your lighting keys, and all you need to do is match the color in your mind to the color of a particular gel. This might not be that easy, though, as there can be a distinct difference between the color of the gel itself and the color that you see when you pass light through it. Also, it can be very difficult to predict how colors will look on skin, on costumes or sets, or when mixed with other colors. For this reason, you should pay careful attention to how colors work in shows you see, and should try to test out colors you are thinking of using by setting up small lighting units, and seeing what the result will be like on skin and costumes.

Which colors to use, and more complex effects like color mixing and doubling gels, split gels, etc, will take some time for you to understand and develop. Indeed, the process will never and, as there are infinite color combinations you can choose, and even very similar-appearing colors can be very different when used on the stage. The following chart summarizes the colors that I use commonly, and my subjective impressions of how they work:

Gel Color	Impressions
R02, Bastard Amber	Warm, neutral amber, mostly whitish, but enhances skin tones and warms things up a bit
R08, Pale gold	Warm, soft gold color, I use this for toplight for a sort of warm angelic effect quite often
R27, Primary red, same as L026	Real red, other reds are too pale. I use this ofter for scary effects.
R47, Light Lavender	Gentle, pale lavendar, looks decent on skin tones, and can serve as a warm or cool depending on what it's paired with.
L201, 1/2 blue	Very neutral cool blue, used to provide cool light or correct naturally warm sources of light. In contrast to some of the Rosco blues, the blue has very little green in it.

Once you have decided on which angles and colors you will use to accomplish your visual images, you can think about which areas your lighting key will cover for each scene. Clearly, if you have a scene that only uses a small part of the stage, you won't need to duplicate the key for that scene in every area, but only in the areas that the actors will be in. There are additional considerations, which will be discussed in the following section.

Lighting Systems

When you start to duplicate your lighting keys into each area, you are creating something called "lighting systems". The general idea here is that a single lighting key is several lights, each pointing at the same area but from a different angle with a different color. By contrast, a system is, say, all the R08 toplights, one for each area. These lights can essentially be thought of as a group, because if you want to create a nice even wash over the stage with that area, you can simply bring all the lights in that system up to the same level (in general), and with just a bit of adjustment, you should have a pretty good wash. Later, when you get to setting up your lights, you should use the patching systems available to you to put each system together, so you can access it more quickly.

In addition to these complete systems which cover all the areas on the stage, or even the partial systems for smaller scenes, you will also need to develop some other more general purpose systems. For instance, you may need to light your set, or your backdrop, with some color, or even plain light just to eliminate shadows. You might also have special-purpose lights not designed for lighting actors or your acting areas, but for other purposes. These types of lights do not generally come from the lighting key, but shouldn't be forgotten as you start to figure out what lighting systems you have.

TOC - Creating A Rough Plot