A Process for Designing Lighting for the Stage (Part 7): Beginning to Populate the Light Plot

Preliminary Lighting Key

Once you have the Lighting Key and the preliminary Magic Sheet(s) described in earlier posts, it is a fairly simple matter to populate the light plot with symbols representing the fixtures that you intend to use.  You do need to pay attention to the throw distances and make appropriate fixture choices accordingly.  You also have to do so within the available inventory.  There is no point choosing instrumentation that you do not have and cannot get.

To the upper right is the Lighting Key from an earlier post.  Note below how the Lighting Designer can use this to populate lights for the 8 major axis (not including the chandelier effect lighting)

Prima Donna plan showing lights from 8 axis

By reproducing each axis for each area the light plot quickly becomes populated as shown below.

Notice that the FOH Boom positions are shown with filled-in instrument shapes in the plan position but that nearby is a front elevation of each position.  It is the front elevation that carries all of the extra information (Channel, Color, Instrument Number, Focus) as well as the symbol that identifies the type of fixture.  This is because, since multiple fixtures reside above and below each other in plan on such a position obscuring one another.  The channel number is indicated within the hexagon.  The color is  shown at the front of the fixture symbol with the focus indicated just beyond the color.  The instrument number reflects the fixture’s position from SL to SR on each horizontal position that is parallell to the proscenium. It is numbered from top to bottom  on vertical positions (and onstage to off if vertical positions have side-by-side stacked fixtures.)  Normally at this point, (partway through the process of populating the plot) the instruments will not have instrument numbers assigned. However, this example shows numbers already in place.  You may notice  that they are not sequential.  The  gaps in the chronology will be filled in once all of the fixtures are shown.

Next time we will add the chandelier effect lighting, the cyc lighting and the specials indicated on the preliminary color key.

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage (Part 6): Creating a Preliminary Magic Sheet

Once you have a firm grasp of the throw distances and fixture capabilities and have made the choices of lighting areas and vectors, many Lighting Designers will begin populating the light plot with symbols representing the fixtures in the locations that they intend to use.  I often take one additional step first.  That step is to create a preliminary Magic Sheet or (sometimes called a Cheat Sheet).  The Magic Sheet is a representation of each area and lighting axis and serves during the cuing and technical rehearsal process as a very quick way to access all of the channel numbers for each area and axis.  Many designers don’t create the Magic Sheet until immediately before they need it in the auditorium, but I find it useful in organizing the channel setup.

There are two basic formats that a Magic Sheet can take in my experience.  The Graphic method is shown below.  It consists of a graphical representation of the lighting areas of the stage organized with arrows indicating the axis of the light beam, and a number corresponding to the channel that controls light from the illustrated axis and into the identified areas.  These are grouped by function or axis as indicated below:

The 2 pages above lay out a scheme for assigning channels to each instrument from the 8 major axis from the Lighting Key.  They also now include color numbers, though this is not strictly necessary at this stage.   The designer’s choice of color will be partially experiential, partially experimental and partially instinctual.  The designer’s choice of colors for a given project will also be relative to conceptual matters as well as practical considerations of textual reference and colors of settings, costumes and cast complexion.

To finish the graphical magic sheet(s) for this production, one also has to make decisions on color and angle of the chandelier effect and motivational light, the backdrop illumination, specials  and any incidental light that might be needed.  Below is that third sheet:

With this preparatory work complete, I am ready to begin populating the light plot with symbols representing the fixtures that I intend to use.

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Determining Lighting Areas (Part 5)

Earlier I described how to figure out the throw distance from a lighting fixture at a known position to a lighting area by creating a section drawing.  Depending upon the complexity of the plot, this might be a daunting task to perform for as many of the fixtures as might require this determination.  It is entirely possible to calculate the throw by calulating it mathmatically from measurements taken from the plan and the center-line section.  This is because, with a quick application of the Pythagorean Theorum (the sum of the squares of two sides of a right triangle equals the square root of the hypotenuse).

In the last post, I demonstrated that a 14 degree Source Four fixture hung on the SR FOH Boom position at 21′ above stage level would throw a roughly 11′  lighting are just upstage of the proscenium and on the centerline of our example stage.  

In plan the throw distance is about 38′.  The elevation of the fixture is approximately 15′ above the face-high lighting area.

The square of 38′ is  1,444′.  The square of 15′ is  225′

The sum of the squares of 38′ and 15′ is 1,669.

The square root of 1,669 is almost 41′

With a  41′ throw, we know from the 19 degree  Source Four fixture multiplication factor of 0.31 from an earlier post that a 19 degree  fixture would render a pool of light with a diameter of aproximately 12 3/4′ (much larger than the diameter of the initial 45 degree SL front-light .  Meanwhile at 41′ throw, the 14 degree Source Four fixture with a multiplication factor of 0.26   would render a pool of light approximately 10 1/2′ in diameter.

Comparison of different fixtures from different axis and angles

While the diameter of the 14 degree fixture  from 41′ is aproximately 12″ narrower than that of the 19 degree fixture from  the 45 degree SL front-light position, the shallower axis creates an elongated ellliptical pool of light quite a bit larger than the first.  Therefore, the 14 degree fixture is probably a better choice than the 19 degree fixture for the shallower axis.

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Determining Lighting Areas (Part 4)

When the designer considers the lighting areas, he or she must consider the shape of the lighting area.  Up until this point, I have described the lighting area by diameter as if the lighting area was the shape of a circle.

Inaccurate depiction of circle-shaped lighting area

In fact, the lighting area from a single fixture, is seldom precisely circular in shape.  Consider that only if the fixture is positioned at a 90 degree angle to the plane which that beam it to strike will the resultant pool of light be circular.  Once that angle becomes shallower than 90 degrees, the resulting shape of the beam will assume an elongated elliptical shape.

Accurate depiction of elliptical shape of lighting area

To the right is a more accurate depiction of the elliptical shape of the lighting beam generated by the  Source Four 19-degree fixture with a 37′-8″ beam throw serving as a 45 degree SL Frontlight to the lighting area.   Also, recognize that a different fixture from a different position would create a different elliptical shape.

Below is the illustration of the beam that results from an instrument at a lower angle and slightly different axis.  This might be a light into this area described as “Low Angle Warm Reflected Sunlight” in the preliminary lighting key.

Elliptical lighting area from a lower angle

Note that the light fixture from this position is switched to a 14 degree fixture. This choice is because the throw distance is appreciably longer at 41′ and because the angle is much shallower.  Next time I will explore an alternate way to estimate throw distance and elaborate on the choice of a narrower-angle fixture for this axis.

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Determining Lighting Areas (Part 3)

Once the Lighting designer understands the beam properties of the available fixtures, has a plan (in the form of  having a lighting key) and has a firm understanding of the theatre architecture and available lighting positions, then he or she needs to determine the throw distance from the lighting areas to the spots on stage.

Lighting Key for production of Prima Donna

Remembering the lighting key that we looked at for the production of Prima Donna, we can begin to determine the throw distances from the lighting positions.

For example:  Let’s begin by planning the light coming into the lighting areas from Stage Left as a 45 degree front light (labeled “Neutral Bounce Light in the key).

Plan View showing the throw of a 45 degree SL front light

The drawing to the left shows a plan view of a portion of the stage with a figure standing on the center line just a couple of feet upstage of the plaster line.    A young designer looking at this plan would be excused for believing that it shows a throw distance of  28 1/2′ from the lighting instrument to the figure.  However, that is far shorter than the actual throw distance.  What is not accounted for in the plan view is the elevation of the fixture above the stage which increases the throw distance.

Section View of the stage through the center line

The diagram to the right shows  the section through the center line.  Notice that the section view shows that the lighting area is calculated at the actor’s face level (from 5′ to 6′ above the stage floor) to account for the fact that providing illumination so that the audience can see the actor’s face and features is one of the main goals of the Lighting Designer.  Again, a young designer might be excused for thinking that this diagram suggests that the throw distance from the fixture to the figure is 33′.  However, once again, that is not an accurate assessment.  This while the section view does accurately describe the elevation of the fixture, it does not account for the angle that the instrument is placed with respect to the center line.

    Section View drawn along the axis of the lighting angle

In order to account for both elevation and angle in calculating the throw distance the designer might create a section drawing through the axis of the throw of the lighting fixture.    Such a section drawing at left shows that the throw from the chosen position should be in the range of 37′-8″.

Using the information from the preceding post, we can determine that a 19 degree Source Four fixture positioned as shown on the first beam position (with a Multiplication Factor of 0.31  will project a lighting area at face level of 11 1/2′ diameter centered upon the figure.  Notice also that if the lighting area moves up or down stage, then the throw distance would change and the diameter of the lighting area would become larger (if the throw distance increases) or smaller (if the throw distance decreases.)

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Determining Lighting Areas (Part 2)

It is important for the designer to understand the characteristics of the beam output for the instrumentation that is available, so as to select the best fixture for the intended purpose.  Remembering that one of the goals is to render an 8′ to a 14′ diameter lighting area on the stage, the Lighting Designer must be able to specify the most suitable fixture.  Often, when a designer is working in a familiar space or with familiar equipment, the designer can work almost from instinct.

However, an inexperienced designer, or a designer working in an unfamiliar space, or with unfamiliar fixtures, would be well advised to do some “homework”.  Below is a table comparing 9 different ETC Source Four fixtures and their related Beam and Field angles.  The diagrams indicate the throw distance necessary to produce a 10′ pool of light (using the Field)

Comparing Field and Beam Angles of ETC Source Four Fixtures

The beam and field angle information comes from the individual online fixture cut sheets available at the ETC web site Source Four Downloads site.  Multiplication factors for beam spread come from the Source Four Beam Spread Table on the same downloads site.  Multiplicate foacors marked with an * are not included on the available beam spread table and have been calculated by the author.  The designer may find information on many lighting fixtures available in the U.S. in the Photometrics Handbook (published by Broadway Press) or in other texts.  However, most manufacturers also offer the information online (as in the case of ETC).

One of the handiest tools available to the Lighting Designer is the “Multiplication Factor” .  This is a number assigned to each instrument that provides a quick aproximation of the size of the pool of light that that instrument will render from a known distance using the following formula:  (Throw Distance) X (Multiplication Factor) = (Lighting Area Diameter).

For example, suppose you know that you have a 20′ throw distance to the lighting area from a lighting position that you intend to use and you want to have about a 12′ lighting area.  You can test each available fixture to determine its lighting area from that distance by plugging the Multiplication Factors for Field into the formula:

Source Four 26 —  (20′) X (0.42) = (8.4′)
Source Four 36 — (20′) X (0.58) = (11.6′)
Source Four 50 — (20′) X (0.93) = (18.6′)

This would suggest that although the 36 degree fixture would yield a slightly smaller diameter lighting area than we hoped for, it is the best (as in closest) choice.  Note that while it is 6″ in diameter narrower than the target size, the next fixture (the Source Four 50) will produce a much larger diameter than desired.

If you didn’t want to run trial and error calculations, you could use the following formula to learn the desired multiplication factor, and then choose the closest best match:

(Desired Area Diameter) / (Throw Distance) = (Desired Multiplication Factor) Thus, with the 20′ available throw distance and the 12′ desired lighting area:  The formula (12′) / (20′) = (0.60) indicates that we are looking for a fixture that has close as possible  to a Multiplication factor of 0.60.  By comparing that value to the values of the Field Multiplication Factor  of the available fixtures, you learn that the 36 degree fixture is the closest.  You would have to run the actual Field Multiplication factor through the first formula again to determine the exact Lighting Area diameter (so that you could plan your areas accordingly)

If the reader is like most of my students, it is at this point that you will realize that all that math from High School actually did count for something!

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Determining Lighting Areas (Part 1)

Once the Lighting Designer has made the determinations of the general decisions on the distribution (directionality, texture, etc.) and the broadest sense of color by creating a Lighting Key, and is armed with an accurate documentation of the set (particularly the plan and section of the setting) and accurate drawing of the theatre, she is equipped to begin creating the Light Plot.

Set Designer’s floor plan for Prima Donna. Notice that lighting positions are NOT indicated.

One note of particular importance is that issue of gaining access to accurate drawings of the theatre.  The designer needs to know exactly in space where available lighting positions exist and how those positions relate to the setting. Often, the Lighting Designer relies on drawings provided by the house or by other collaborators.  If nothing better is available, then this may have to suffice.  However, nothing beats a site visit and personal observation and making measurements in person to assure that the lighting design is predicated on reality and not upon errors and omissions in some other collaborator’s documentation.  A Lighting Designer who neglects to assure themselves of the accuracy of the drawings, has nobody but themselves to blame if inaccuracies create problems for her on down the line.

A next step in the process of beginning to draw the light plot is for the Lighting Designer to determine how best to divide the space up into “Lighting Areas”.

There are a couple of strong reasons for creating lighting areas.  The foremost is based upon the intersection of the goal of “Selective Focus” and the requirements of the text, the directorial and design concepts, and the actor’s movement and location on stage during important moments of the play.  In the example above, we might need to isolate the center of the stage between the table and sofa because a lot of action takes place there.  Likewise the center of the apron.  The areas in front of each upstage door, the center balcony window, in front of each wardrobe, the sofa, the table, all might be areas that the designer might need to have the ability to light more brightly relative to the remainder of the stage at some point during the play.  Not all of this might be able to be accommodated with Lighting Areas, but a designer would do well to determine what is ideal for the production, before limiting herself to what is possible under the given circumstances.

Another important reason for dividing the stage into lighting areas is the fact that in order to achieve adequate level of brightness and even coverage of the stage from a particular axis (and to maintain that axis across the width and depth of the stage) the lighting designer will have to use several fixtures focused at different areas of the stage, but at the same angle to their respective areas.

The number and size of the Lighting Areas that the Lighting Designer will need to plan for is, in turn, dependent upon a few key factors as well.  We will explore those factors next time.

Meanwhile, in order to create the smooth wash of light from one area to another, adjacent areas typically overlap by a certain percentage as indicated in the diagram below  This takes advantage of the optical properties of the beam and field angles.  Whereas the beam angle is the cone of light that varies no more than 50 percent of the brightest portion of the light output, the field angle consists of the cone of light that diminishes to as little as 10 percent of the brightest area of the light output.

A diagram of three adjacent lighting areas

As a general rule of thumb, the Lighting Designer should plan on each lighting area being between 8 and 14 feet in diameter.  The diameter will, in turn depend upon the throw distances between the lighting positions and the stage and the beam spread of the available instrumentation.

See future blogs for subjects that address subsequent steps in the process of designing lights for theatrical production.

That’s enough for now! Have fun!  Be safe!

SJM

A Process for Designing Lighting for the Stage: Creating a Lighting Key

For many years, I have adhered to a particular process when designing lighting that includes the creation of a Lighting Key (a graphic representation of how I imagine a production will be lit.

Of course, this process begins with a thorough reading of the text, a study of directorial and collaborative colleagues’ conceptual ideas, A close examination of the preliminary (or finished) set and costume designs, the creation of a preliminary cue list based upon close reading of the text and any preliminary run through of the play that I can watch.  Armed with as much of this information as I can gather, I am ready to begin imagining how I am going to achieve the director’s and my vision for lighting the production.

A Rough Sketch of The Set Design of Prima Donna

The first step is to be to create an abstract plan view of the stage starting with symbol that will represent the actor in space.  Sometimes I just use a letter (such as the letter A).  Often I choose a plan view of a human figure.  Then, bearing in mind the functions of lighting (particularly Visibility, Selective Focus, Modeling, Mood, Storytelling, Reinforcing Colleagues Choices), and the intersection of the textual information and the environment of the setting, I begin imagining how lighting might effectively support the production.  Below is the example of a lighting key for a production of Prima Donna (a one-act opera by Arthur Benjamin).  In this production the setting is in an Islamic-inspired room with windows overlooking a Venetian canal. The scene starts in a largely empty room.  The occupant is in financial trouble and his furnishings have been confiscated, hence the room is largely empty of furnishings. The time is late afternoon.

Note that the warm afternoon sunlight is described as coming from the back stage right and reflected afternoon sunlight from the SL front at a low angle.  Meanwhile a top light in a color suggestive of bounce light from the sky is called for as well as a fill light of cool or neutral from SR front for the sake of visibility.  The actual colors are not specified (as in the gel colors from Rosco, Lee, Apollo…etc.)  Rather functional descriptions serve to explain the relative color.  The actual color will be chosen once the set and costume paint and fabric colors are known and once the entire lighting scheme is decided upon.

By the end of the first scene, the resident has made preparations to entertain his wealthy and influential uncle.  Furniture is rented and delivered, food procured and entertainment in the form of two chorus girls both masquerading as a certain opera diva (instead of just one) arrive to entertain the lecherous Duke.

The second scene occurs an hour after the first, but for reasons of heightened passion, the director wants a very nighttime feel to the scene.

Notice that the moonlight lights the room from back SL with reflected moonlight from FOH SR.  A top-light reinforcing a nighttime look and fill light from FOH SL serve to complete the general illumination for the scene.  And added feature of this scene is the chandelier, which should appear to be providing the illumination for the scene.  This light breaks down into an overall front-light to provide warmth to the faces and an effect light that will be a steep back, top, or sidelight, depending on the relationship of the lighting area to the chandelier.

Putting both together, we arrive at a comprehensive lighting key:

Notice that each lighting area will have as many as 10 fixtures focused into it.  Also recognize that this key is just dealing with the main playing areas.  Ancillary areas such as out on the balcony, both upstage R & L doorways, lighting the drop seen through the arched windows at the back of the setting and any specials that might be required, will require additional lighting and additional fixtures.

See future blogs for subjects that address subsequent steps in the process of designing lights for theatrical production.

That’s enough for now! Have fun!  Be safe!

SJM

The Function of Stage Lighting

At some point the examination of the procedures and equipment used  for stage lighting, the theatrical lighting designer needs to consider the role that lighting plays in a theatrical production.  Variously called the “Lighting Designer’s Goals” or the “Functions of Theatrical Lighting” there is no definitive list that I have come across that meets my aspirations for a completely symmetrical and succinct listing.  Each time that I teach this concept to students, I adapt the presentation to include new ideas and understanding.

I usually begin the conversation of the “Functions” of theatrical lighting on the text by J. Michael Gillette entitled Theatrical Design and Production:  An introduction to Scenic Design and Construction, Lighting, Sound, Costume, and Makeup (in its sixth edition at the time of this writing).

Visibility

The first and foremost goal of the lighting designer must be to provide the illumination necessary for the audience to adequately see the performer and to perceive the performance.  If there is anything like a hierarchy to the functions of theatrical lighting, then it is my opinion that visibility is the most important.  If a lighting designer is incapable of achieving any of the other functions (due to limitation of time, resources or skill) then it is of paramount importance that the Lighting Designer achieve at least this goal.  Without it, the adage “if you can’t see ‘em, you can’t hear ‘em” will likely doom the production.

Selective Focus

This function is on its most basic level almost the automatic result of theatrical lighting.  The act of illuminating the stage and leaving the auditorium in relative darkness immediately creates a situation that the audience will be inclined to direct their attention to the stage.  This function can be taken much further, by directing the audience’s attention to the actors, while illuminating the environment to those levels that achieve the overall visual goals of the production.  Further focus can be directed to certain characters or performers for certain sequences or moments when it is in the interest of the theatrical production that the spectators should be directed to attend to them.

Modeling

This function calls for the lighting designer to be mindful of the 3-dimmensional aspect of theatrical performance.  This goal will be manifested differently from production to production and among different modes of theatrical production.  For example, a dance or movement performance may require heavy emphasis on the sculptural qualities of bodies moving in space.  Alternatively, for a language-based performance, the Lighting Designer might need to concentrate attention on illuminating the environment in appropriate and interesting manner and in separating the performer from the scenery with light.

Mood

When young designers approach lighting design, this is the function that seems most appealing and important to them.  It is also the function of lighting design on which most energy is spent when in discussion with directors and other collaborators.  Read any lighting design concept paper and it is most likely that defining and achieving the mood of the production is the major topic of examination.  Just as every production has some kind of concept, every production will have some level of mood that the Lighting Designer will achieve (either by intent or through accident). Often that mood is attached to some aspect of realism, but is also integral to the production.

These four goals don’t seem adequate.  It has always seemed to me that four or more additional goals must be considered:

Story-Telling

The lighting designer needs to satisfy obvious dictates of the script in a language-based production.  This may mean portraying a lightning storm, a sunrise, an aurora, a starscape or blazing sunshine in service to the author.

Reinforcing Conceptual and Design Choices of other Collaborators

Similarly, the Lighting Designer will need to reinforce other choices related to the directorial concept or to the choices of the other design collaborators.

Rhythm and Punctuation

Perhaps very much related to story-telling and to conceptual choices (particularly related to directorial concept).   This goal is focused on the pace of the show and toward the journey that the designer takes the audience on as she constructs the speed and character of the lighting transitions and the contrast between lighting states from one sections of the performance to another.

Coolness factor

A director colleague of mine uses this phrase whenever his concept is calling for some production element that is primarily intended to heighten the spectacle of a production.  This function can quickly devolve into pandering to the lowest common denominator…sort of a bread-and circus for the masses.  On the other hand, sometimes a splashy gratuitous effect is just the thing that is needed.

I believe that being mindful of your goals, you can make better and more informed choices.  Remember too, that every designer will probably have a slightly different perspective on the functions of stage lighting and that the role that stage lighting plays may vary from production to production and from theatrical mode to theatrical mode.

Enough for now!   Have fun!  Be safe!

SJM

February Lighting Links

Occasionally, a blog such as designandtechtheatre can (and should) call attention to some of the most useful and pertinent digital web recourses that touch upon the subject.  Following are some such resources that I have come across over the past few weeks in my examination of the subject of Stage Lighting and the evolving technologies:

Professional Lighting Resources — Bill Williams

This site features a number of categories.  One section entitled Stage Lighting 101 is of particular interest purports to be a “quick reference for the lighting student, educator, or professional”.  Bearing a copyright notice of 1990-2003, the page claims to be “revised and updated often” but bear no evidence of having been revised recently.  Nevertheless, it is a very interesting site.  Of particular value to someone interested in lighting practices is the page linked to the 200 – Design Methods link

Effective Lighting Design A to Z —  by Mark Harvey

is a really helpful primer that breaks the lighting design process into 26 steps (A through Z). Each step is described by a terse description followed by a succinct sentence or three of description.  Useful diagrams illustrate complex ideas and provide examples of the step and many terms are emphasized in red, while in a few instances more complex examples are provided as links that typically open in the same window.  The site might be improved by allowing the reader to link to the highlighted terminology for examples or fuller descriptions and the 26 steps seem arbitrary and forced, but the site can serve as a very workable template for a young designer’s first few lighting designs.

Stage Lighting for Students — by Jeffrey E. Salzberg with Judy Kupferman

This site purports to be a resource for students and provides a perspective on stage lighting design.  It consists of many pages navigated using an index of links in a sidebar to the left of the main window.

USITT RP-2, Recommended Practice for Theatrical Lighting Design Graphics – (2006)

This site consists of a single PDF.  It is an instructive, rather prescriptive written outline of the characteristics of the drawings, notably the Light Plot (plan) and the Section drawing.  The drawing concludes with a rather comprehensive compendium of USITT endorsed and recommended symbols of different types of lighting instruments for use on light plots.

 

The Lighting Archive — sponsored by the New York Foundation for the Arts

This site features examples of work by important lighting designers and currently links to extant plots and paperwork from Jean Rosenthal, Ken Billington and Gilbert Helmsley.  Each project is fairly well represented with complete paperwork and should prove fascinating and instructive to students and experienced designers alike.  It appears that the site is evolving and that examples of additional designer’s work are likely to be added in the future.

The New York Public Library & The Lighting Archive Theatrical Lighting Database

Like the “Lighting Archive” this site archives a select number of projects by important lighting designers.  These projects include: A Chorus Line (1975) by Tharon Musser, Fall River Legend (1991) by Thomas Skelton, Hair (1968) by Jules Fischer, and Sunday in the Park with George 1984) by Richard Nelson.  Each project includes numerous documents.

Please visit these sites to learn more about the process and paperwork of the lighting designer.

Have fun!  Be safe!

SJM