Today I want to give you an intro to the ESP8266 WiFi microcontroller. This module is incredibly small and thin at only 16mm by 24mm and 3mm thick. It has 22 pins to allow it to connect to a large range of other devices, like LEDs, relays, OLED displays and more. It runs off of 3.3V with a Standby power consumption of less than 80mA. It supports 802.11 b/g/n over a WPA/WPA2 connection. Which mean it will work on a standard wireless internet router. Because of the wireless support that this device has it can easily receive lighting data from a light board over sACN or E1.31. People also have it configured to work with Art-net as well.

With a little bit of work you could build your own lighting instruments and run them from the standard lighting console. But beyond that the use of MQTT in a theatrical setting could be incredibly powerful for automation. An actor could press a button connected to this device and it could send a cue to the lightboard to update or have a sound effect play with a MIDI trigger. It can be used as a bump switch so that if a piece of scenery is moving and there is something in it’s way it’ll stop by cutting power to the system until the obstruction is cleared. It can also be connected to sensors to relay information back to stage/house management and other technicians. These devices go anywhere from 3 dollars all the way to 5 dollars and are always in stock. Below I have some links in where you can buy some and also the documentation of the device. The ESP8266 12e module is perfect for a theater on a budget or even for a show that requires a lot of unique or special effects. These devices are easy to program and even, once configured, can be programmed Over the Air so that once you build a peice of scenery or a light you don’t have to tear it apart in order to reprogram it. But currently there is a downside of using these modules which is a lot of tutorial series are hard to follow and are extremely long. They assume you have the technical knowledge to be able to program and understand networking which a lot of theatre professionals don’t know the systems in extreme technical detail.

Now a concern that I could see is that in theatre we are always told to be afraid of wireless technology. A wired connection is better. But I think the ESP8266 12E modules are very different. The big problem with wireless technology that is built for theatre is that there is no error checking; like with wireless DMX or even E1.31. They are sending over 638 bytes of data within a packet that could easily get lost. But if you’re using one of these wireless modules it is easy to set up error checking with MQTT and have the ability to program in other options if there is an issue. I could see these devices being used inside of costumes running off a battery and powering LEDs and I believe that they could be just as stable as professional solutions.

If you do the cost benefit analysis it looks like these devices are a great value and they are but there is some technical expertise that you need to have in order for these devices to be useful for you. Over the next few weeks I’m going to be playing with these devices and starting to get them to interface with standard lighting technology like the ETC ION light board and QLab, an audio and projection control solution.

If you’re interested I have links down below to where you can look at the ESP8266 12e documentation.

https://www.kloppenborg.net/images/blog/esp8266/esp8266-esp12e-specs.pdf

Last week we discussed RDM, a networking protocol for management and monitoring of different devices connected over a DMX network. This week we’re talking about Art-Net, a competitor to sACN, which both carry DMX data. The biggest advantage to Art-Net over SACN is its capability to carry RDM data. While its theoretically possible to use RDM over sACN E1.31, it is not supported. Art-Net uses many nodes and one server to communicate. Allowing different nodes to subscribe to publisher nodes which send the data.

Art-Net uses two different groups of packets, discovery and streaming. All packets are sent over UDP meaning a faster protocol but less reliability that the packet will get to its source. Discovery consists of two main packet types, ArtPoll and ArtPollReply. ArtPoll broadcasts that a node is interested in finding who else is connected to that network and all devices, including the sender, respond with an ArtPollReply containing info about the device like its IP, manufacturer info, and human readable reports on its status. The main streaming packet is ArtDmx which is sent to a specific port address for nodes to process DMX data. These packets only contain changes in data and are not intended to be sent every frame. While this is true, a node should expect a ‘Keep-Alive’ packet every 4 seconds affirming the current state. In streaming there are also packet types to keep a show synchronous or non-synchronous. There are also packet types to set the real time clocks in devices and to send macro triggers to the network. Along with these there are file transfer packets to update the firmware on lights.

The website art-net.org.uk contains some useful C++ code snippets describing how to program the protocol.

Sources:

https://art-net.org.uk/

Last week we discussed the modern technology that allows theaters to be as big as they are by allowing 512 channels over ethernet, sACN. The biggest flaw of sACN is that the protocol just carries DMX data and will need some sort of converter or gateway to extract the DMX data from the packets and send it to the right place. Devices like this are expensive and might make SsCN not worth it for some people. This week we’ll cover RDM, a protocol that doesn’t need a gateway or any converter and is capable of operating over a standard DMX cable in parallel with standard DMX data. RDM is not meant for controlling lights for a show but is meant to give designers the ability to monitor lights during a show. RDM is mainly used to Identify connected devices, configuring these devices, sending data to those device, and finding problems with those devices. While DMX can only send data from the controller to the light, RDM allows for lights and other RDM capable devices to send status data back. This protocol was first developed by the Entertainment Services and Technology Association (ESTA) and the technical name for RDM is ANSI E1.20. RDM data packets are sent in between DMX data packets and is meant to not disrupt legacy devices that are no RDM compatible. While DMX was originally designed to have two of the pins on the connector reserved for the future, some manufacturers started using those pins for proprietary purposes. Because of this, RDM must work over pins 2 and 3 (the same as DMX) as to not interfere with these proprietary communications. RDM is intended to be sent between DMX packets but because nothing is perfect, there are concerns of data interference between the two protocols. The RDM standard intends to fix this by only having one device transmit at once (except for specific pre-show setup times). This minimizes any chance of collision. This specific pre show time is called discovery where the RDM controller sends out the command and all RDM devices send their data back at the same time and using search algorithms it will resend discovery commands with refined filters based on device IDs and mute devices it’s already found. If the controller needs to send messages quickly, it uses broadcast communication. Because any device can receive these messages, the only messages sent using broadcast is the discovery messages. For every other message send from the controller, Unicast communication is used on a request response pattern. The controller sends the request to the ID of the device and waits for the device to respond. RDM is mainly used to Identify connected devices, sending data to those device, finding problems with those devices, and configuring these devices. RDM is not very compatible with sACN because RDM assumes that the DMX is data is being sent through one universe over DMX cabling where sACN uses multiple channels over ethernet. This makes it impossible for an RDM controller that uses DMX to receive messages sent from a RDM controller on ethernet.

The RDM specifications that were used to help write this piece can be requested at:

http://tsp.esta.org/tsp/documents/published_docs.php

And a forum all about RDM can be found here (where the title draws homage):

http://www.rdmprotocol.org/

We talked about DMX last week and one of the biggest problems discussed was the limitation to only 512 channels. DMX was not created with the foresight that some lights might be channel hogs and the need for more channels was born, this is where Architecture for Control Networks (ACN) comes in. The first release was ANSI Standard E1.17-2006 and was revised again in 2010. Most likely the main reason we still use DMX today is because of its modularity making it adaptable to whatever needs that might arise in the future. The idea of modularity was not forgotten for ACN which is divided into multiple different protocols. The first protocol is the Common Architecture which specifies a format of multiple PDUs or protocol data units part of which must be the Root Layer Protocol. These PDUs are used to connect the multiple higher-level protocols. Next is the Session Data Transport (SDT) which us used when broadcasting using multicast over UDP. This provides reliable multicast support so that packets have assurance that they’ll find their target. The other great feature of SDT is the ability to customize the tradeoff of latency, level of reliability, and processing power. Allowing for better scalability on large or small number of connections. The Device Management Protocol (DMP) allows any device to be represented as a set of addressable value to represent its desired state. While what we have talked about so far has operated over UDP and multicast, the DMP has been operated over TCP to provide reliability. The Device Description Language (DDL) allows programs to understand the description of the interface and capabilities of any device to be networked with. The DDL is XML based and can be downloaded from each device itself or over the internet. Most controllers will contain a cache of different devices commonly encountered. The last is Interoperability profiles (EPIs) which act as an internal service discover in a system mainly helping with multicast over UDP. The first major extension of this protocol is E1.31 also known as sACN or Streaming ACN. ACN has been implemented in multiple different pieces of hardware and software but nowhere is it more prominently implemented than by Electronic Theatre Controls (ETC) who based their own line of control infrastructure on it.

An implementation of E1.31 can be found on a shared repository from Nicholas and I.

Here is the link if you want to take a look!

https://github.com/nicntj/sACN-E1.31

Sources:

http://powers.media.mit.edu/wiki/upload/E1-17ACN2006DDL.pdf

http://www.rdmprotocol.org/files/What_Comes_After_Streaming_DMX_over_ACN_%20%284%29.pdf

This is the first technical piece in our series. Up until now the posts have been more design focused while this will cover the technical aspect of the protocol used to connect every light seen on a modern stage. DMX512, or as will be called from here on out DMX, is the main protocol that connects lights and sometimes other features on a stage. DMX was created in 1986 by the United States Institute for Theatre Technology (USITT) as a standardized method of connecting lighting consoles to dimmers and was revised in 1990 to what we know today to allow more flexibility. DMX is most commonly found today as a five pin XLR connector called XLR-5. The first pin is ground, the second two are data, and the last two are optional data pins. Because the last two are optional, DMX can also be found as a standard 3 pin XLR connector. The data that goes through this connection is asynchronous serial data at 250 kbit/s. Each packet of data also includes a start code which signifies what kind of data is being sent so devices can understand how to act on the data that is being sent to them. An important part of this data is that it has no parity bit, meaning that all DMX data that is sent has no error checking and any device receiving this data must accept and act on it all at face value even if it has been corrupted. Therefore, it is advised to not control large motors or pyrotechnics over this protocol. DMX allows for one controller to connect to many fixtures through daisy chaining them together. Each device will have a DMX in and a DMX out to allow the continued connection. At max capacity, one controller could talk to up to 512 different devices through the channel system. Lights are connected one or more of the 512 channels that gets controlled through the protocol. A dimmer may just need one channel because it just has one feature, its brightness while an RGB light may have 4 channels: 3 for each color and one for brightness. This protocol is very expandable to allow basically anything someone could imagine. This and the fact of the robustness of the cable has created the popularity for this lighting control protocol.

Pros:

• Ease of use and quick set up
• Durable Cables
• Used on a variety of lighting fixtures (LEDs, dimmers, moving lights)
• Daisy-Chaining

Cons:

• Zero error checking
• Limited range without repeaters

References:

http://pangolin.com/LD2000/dmx-about.htm

http://cache.freescale.com/files/microcontrollers/doc/app_note/AN3315.pdf

Before we get into all of the technical details of different lighting protocols and how they work, establishing a healthy idea of what lighting design is might be helpful. The design is going to effect a lot of properties like what type of lighting fixture to use, color, texture and placement of the fixture. A good lighting designer doesn’t just start hanging lights and adding random colors that they think would look cool, but instead a lighting designer needs to look at what the project entails. If they are doing a theatre piece they must read it, understand it, and have a conversation with the director about the emotion, time and atmosphere of the play or musical. Maybe this particular lighting designer is working in a concert setting. Listening to the music beforehand or understanding the genre of the band that is playing is incredibly important. But the concert lighting designer might not even be able to listen to the music! They instead need to create a design that is flexible and can change based on the live performance. No matter the type of lighting the architecture of the space is going to drastically change where to place the fixtures. This architecture could be built into the performance venue or it could be added staging as in a scenic design for a musical or play. And that is just a little bit of the problems that lighting designers face when working! There is a lot of information to keep track of as a lighting designer and for beginning designers it can be quite stressful. I’m going to break down how I design and my thought process. With a little bit of practice it gets a lot easier to manage all of the little nuances within designing!

 I first would like to start with a definition of what I think a good lighting design does for an audience. This definition is purely opinion and as a designer works in the industry it can certainly change. But it’s a good framework to start to wrap our mind around. I believe the importance of lighting is to create atmosphere above everything else. There’s emotion in light. Red is frightening, blue is calming and pink might show love or playfulness. These colors and their association with emotion is deeply ingrained in our culture and who we are as human beings. When there is lighting on stage, on objects or even in the outside world I think of it as a fabric that drapes onto the objects and people. It adds to the form that it is shining on and gives it a brand new look. But we as lighting designers need to make sure that we keep this atmosphere contained. It’s easy to create cool effects and have a bunch of different colors but the lighting needs to add to the atmosphere on stage. If there is a play where a girl and guy are falling in love red lighting that is shooting up on them from a low angle might be the wrong way of representing their growing passion. But maybe that would work in a murder scene. It’s all in the atmosphere of the theatre piece or concert. Lighting shows time, space and change over a given piece of work and that is all attributed to atmosphere. For a concert setting some songs can be warm or cold, sad or happy, or angry or peaceful. With those words there are images of color that we can play with in lighting. When I listen to music or read a play I get images in my mind of what they look like and the feelings that they give me. For me it’s very easy to see the music and feel what color it should be. It’s also a skill that gets more developed over time as new ideas emerge.

Planning and Plotting

UWM’s Production of 12 Ophelias (Lighting design by: Stephen Roy White, Scenic design by: N. T. Johnson)

 The theater can be an intimidating place to start working. For the University of Wisconsin- Milwaukee’s production of 12 Ophelias there were about 152 lights hung in the air to be able to cover the whole stage. That can be a lot to keep track of for a designer. But to make it easier to determine where lights need to be and what angles, lighting designers often simplify their design by using a Lighting Key as a way to plan before moving onto a light plot. This example key is very simple. Imagine a person is in the center and the arrows are where the light is coming from. With this key I’m imagining a scene in the play where it’s beginning to become a sun rise. On each of the arrows I put a color that will be put into a light. Then what I can do from there is test it under lights in a smaller setting to make sure that I get the feeling of a sunrise. This step is also good as a research phase. Always look up pictures of ideas that you want to replicate so that you can get it as accurate as possible. Young designers often guess what natural lighting looks like and it’s never quite right. Even though you’ve seen a sunrise a thousand times it doesn’t mean you remember all of the details that make it realistic!

That is an example of a plot that I created in class. The red lines represent pieces of the scenery that I was imagining and then I had to figure out where I was going to put my lights! A light plot shows the master electrician where to hang the lighting fixtures and what type they are. This document serves as a working document for grouping, numbering and patching these fixtures. It can also contain what dimmers the fixtures are plugged into.

This is a closer view of the plot. I also turned on the different pools of light that are seven feet in diameter. This is where I want the lights to be pointed at. It is common practice to overlap these circles of light to allow for the best amount of coverage available. To start filling in the plot, it is helpful for us to refer to the lighting key. Imagine that each pool of light needs to have the same angles of light that your lighting key does. For this plot the pink circles have a lighting key that has back, font, right side, left side, and top light. Every pink circle needs to have five lights pointing in the different directions to reach the center. But it can’t be any old lights we need to use math to help us determine what lights we should be using and their placement.

 
This chart shows the distance at the top for how far the light is traveling and the other numbers are the diameters of the pools of light at that given distance. For this chart the lighting instruments being used are in the ETC Source Four family of fixtures. A different chart and specifications would be used for other brands of lights. The designer needs to do the math in order to pick the lighting fixture that will create about a 7 foot diameter circle of light. The Pythagorean theorem is a lighting designers best friend in determining the hypotenuse of the triangle. (Also you could use x√2 as the hypotenuse. Where x is the floor or vertical distance)  The ‘A’ and ‘B’ sides are the floor distance and the vertical distance from the light to the ground. The goal is to create a 45-45-90 triangle for each fixture so that they all blend together because they are at the same angle. Also this is generally the most flattering way to light up someones face without there being shadows that might make the subject look older. Hanging three lighting instruments using this method helps make the subject look like they have a lot of dimension since the light is surrounding them versus having one side of them lit up. That is big deal especially when working in a thrust theatre space like the MainStage Theater at the University of Wisconsin- Milwaukee.

After the Plot

The design is then hung in the air after the light plot has been finalized. All lights get plugged into circuits or if they are DMX devices like LEDs get plugged into the network. All lights get color, and if it’s necessary get a gobo which is a texture that is added into the light. It is then up to the designer to control all of the fixtures and create the cues based on the show they’re working on.  

Creating a lighting design can be a very long and tedious process. Going from reading the play-research-lighting key-lighting plot-hanging lights-circuiting-coloring-adding gobos-patching and programing cues for the given show. But it is a very rewarding process when it all comes together.

Next week we are looking into our first protocol- DMX! Thanks for reading!

References:

Gillette, J. Michael, and Michael McNamara. Designing with Light: an Introduction to Stage Lighting. McGraw-Hill Companies, 2014.

Last week we very briefly went through the history of lighting technology and this week’s topic is on lighting design. But before we dig in to lighting design I want to show you basic lighting equipment and why we use them in lighting design.

In the previous article we talked about the ERS spotlight (Or in our case ETC Source 4s) that uses two plano-convex lenses to focus the lighting onto the stage. In theatre that is the main way that we do lighting. We use over 100 ERS spotlights that are pointing in different directions and we use the lenses to blend them together. We also use PAR cans as a flood light to generally light an area. Those types of fixtures don’t have two lenses and generally have a soft edge. They also don’t have any shutters, unlike the ERS spotlight, which block the light from going into places we don’t want like an audience area. There are many uses for the PAR can light but it is typically used as top lighting because of how it spreads light.

The dimmer rack allows for the control of all of the incandescent lighting fixtures. Each fixture plugs into a circuit that can be individually controlled. The dimmers change the voltage waveform which allows the light to be bright or at a low intensity. Each circuit is capable of 256 levels of intensity from zero being off to 255 being completely on. The dimmers are connected to the lighting network to allow them to be controlled by a lighting console. Non-incandescent fixtures like LEDs are not plugged into the circuits. LEDs need a constant voltage in order to run but they can be plugged into a circuit if the circuit has a relay which keeps the voltage at a constant level just like if you plugged it into a standard socket. That is often called parking the circuit since you are keeping it at a specific level. Lights like LEDs, once powered, are then controlled via DMX and connect to the lighting network.

A lighting console is then used to run the dimmers and other DMX capable devices. At the University of Wisconsin-Milwaukee the board used in the MainStage theater is the ETC ION. On the light board you can control lights individually, as groups or even apply effects to them like a strobe. LED fixtures can be set to specific colors using a color picker or if you have a color in mind the RGB values. A lighting console is really when a show comes to life and playing with levels, fades and effects can really add to a performance. A lighting console can also just be a normal computer with software that allows control of the network. ETC makes a virtual console called ETCnomad which is in the EOS family of software just like the ION. The software is free from ETC but requires a special device to output the DMX/E1.31 signal into the network. There are also free lighting console programs like sACN View and OLA that allow for control of the network over E1.31 with ethernet and several other protocols. But unlike the nomad software they are very much limited unless you know how to code your own interface.

Each theater has their own equipment and a way of connecting it all together. We are lucky to have a very powerful lighting network here at UWM that allows everything to get connected very easily and efficiently!

In our next article we will go over the basics of lighting design! Thanks for reading!

SURF Grant Introduction

One cup of engineering to two cups of art is the perfect way to describe lighting design. Engineering is necessary in order to have incandescent bulbs, LEDs and some sort of control, whether computerized or manual. But there also needs to be a reason why this technology should be used. The story needs to call for it, the music needs to support it, and it should be used to create an immersive atmosphere. When I think of theatre, musicals, and concerts there is this delicate dance of the different design elements. The scenery, sound, lighting, properties, costumes and movement on stage all need to work together in order to create a beautiful piece of visual and auditory art. When I watch something that is incredibly balanced with all elements working together I get shivers up my spine. I feel like I’m part of the moment on stage and I’m actively participating. This is what separates live performances from anything prerecorded; the feeling of being surrounded by a story or music. It is a feeling like no other and I believe it is my job as a designer to deliver this experience to everyone that sees my work.

With this SURF grant our goal is to explore lighting protocols and how they work but also detail how they can be used to create visual art. Some of the work we are documenting will have example code that can be used to explore the protocols but it’ll be up to you to find an application to create your art! We will also go into the history of different technologies and explore what the lighting industry has to offer every week. But first, in order for us to start talking about lighting protocols, we need to go through some history of lighting technology and then next week we’ll talk about the principles and basics of lighting design.

Brief History of Lighting Technology:

The most basic use of light comes from the Sun. Now although we have very little control of the Sun and the weather, ancient Greeks and Romans harnessed it’s power to light their productions. They had to think about where their theaters were built in order for the sun to be behind the audience and shine onto the stage. They would carve their theaters out of mountains and create huge amphitheaters to allow for the most people to attend, and
perfect auditory and lighting conditions (Gillette 37). But of course the Greeks and Romans weren’t the only ones to use sunlight. One of the most famous examples is from Shakespeare’s Globe Theatre. Which was designed to have an open roof to let the Sun light the performances (Gillett 44). There is a lack of control when working with the Sun outside and quickly theatre started to move indoors.

As theatre was transitioning indoors it was lit with candles, torches and lanterns. But these early forms of lighting weren’t bright enough for everyone in the theater to see. They developed special chandeliers with reflectors on them to help shine the light on the stage without spilling light onto the audience. It also became practical to put lamps and candles on the front of the stage in order to produce more light, these are referred to as footlights. Although the footlights helped, they needed to add candles and lamps on the wings of the theater to provide more light for the actors. But it still wasn’t enough and there wasn’t much control (Gillette 45). In the middle of the performance the candles could burn out. And if the space was lit up by chandeliers it was a significant amount of work to get all of the candles ready by time of the performance.

Theaters continued to use this kind of candle and lantern lighting for decades and they would continue to develop more advanced reflectors. In 1792, William Murdock developed how to use coal gas for lighting. The gas lighting systems were installed in all kinds of buildings from mansions to business and of course to theaters. (Britannica). The two big benefits of this kind of lighting is that it is extremely bright and can be easily controlled. In theaters with gas lighting there were control valves called gas panels and gas tables, with these valves crew members could control the intensity of the flames for the first time. Although there were some big benefits to this kind of lighting, it still contained an open flame and there was a chance of fire (Gillette 46-47).

In the mid- to late 1800s the light bulb became popularized and a staple of modern lighting technology. It contained the ability to get controlled through dimmers much like the gas light control panels but didn’t have as much of a chance to start a fire with it’s relatively low heat. Through years of development the incandescent lamp allowed for brighter light and longer lasting bulbs. But it’s not all about how bright the lamp gets, it’s also important where the light ends up. There where huge advancements in reflector technology as well as optics that allowed for a more controlled placement of light. The use of Plano-convex lenses helped focus the lighting onto a given area and allowed multiple plano-convex lighting instruments to blend when lighting a large space. These lighting instruments are often referred to as Ellipsoidal Reflector Spotlights (ERS) and are a type of standard theatrical light (Designing with Light 62). Another big development is the use of LED (light emitting diode) technology. LED lighting instruments either have separate red, green, and blue LEDS that mix together to create different colors or they have the RGB diodes built into a single LED. A major advantage is the possibility to create millions of colors and these fixtures can often color match with incandescent lighting instruments to provide almost seamless blending. In the recent years this technology has grown to be brighter and have more control over incandescent lamps but the price point is still very high for LED fixtures (Designing with Light 170-171).

Along with electricity also came the computer. In 1975 Tharon Musser, a Broadway lighting designer, wanted to use a computer memory lighting system to control the dimmers in the Shubert theatre for A Chorus Line. This was the first time this technology was used for lighting on Broadway but quickly became a common practice (Wild, Larry). Lighting manufacturers needed to come up with a way to transfer data from the computer lighting consoles to the dimmers and other devices. Manufactures began to develop their own proprietary data transfer system until the invention of DMX512 in 1986. It was then adopted as the standard way to send data by USITT (United States Institute for Theatre Technology) and manufactures used this method in order to allow many different lighting devices to interact (USITT). The latest biggest advancement has been through networking technologies that allow for the transfer of DMX data over a network. The University of Wisconsin- Milwaukee’s newly renovated MainStage Theater has a lighting network that allows for data transfer over the air as well as a wired ethernet connection. This allows the lighting console to be anywhere in the theater and allows for sACN/E1.31 capable devices like phones, tablets and personal computers to control the lighting system. It also allows for a free placement of LED lighting fixtures and moving intelligent fixtures.

We’ve come a long way in how we control lighting for our performances. It all started with candles and lanterns but now all I have to do is plug my laptop into a network and I can get designing with hundreds of different DMX and sACN devices. In only a little over 100 years we went from just starting to be able to harness the power of electricity in theatre to an immense amount of control. It makes me think about the next hundred years of lighting technology. What advancement in technology is going to be next? What new networking solutions are going to develop? Hopefully through this SURF grant we’ll be able to think about these questions and maybe even explore some solutions. It’s an exciting time to be working in theatre production and technology. And it’s just the beginning of our journey going through it.

Look forward to next week where we talk about lighting design and get into additional lighting terminology!

References:

Britannica, The Editors of Encyclopaedia. “William Murdock.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 1 Feb. 2018, www.britannica.com/biography/William- Murdock-Scottish-inventor.

Gillette, J. Michael. Theatrical Design and Production: an Introduction to Scene Design and Construction, Lighting, Sound, Costume, and Makeup. McGraw-Hill, 2013.

Gillette, J. Michael, and Michael McNamara. Designing with Light: an Introduction to Stage Lighting. McGraw-Hill Companies, 2014.

USITT. “DMX512 FAQ.” Archive.is, USITT, 16 Apr. 2013, archive.is/20130416024656/http://www.usitt.org/content.asp?contentid=373.

Wild, Larry. “Lighting Control System.” A Brief History of Theatrical Scenery, 14 Sept. 2015, www3.northern.edu/wild/litedes/ld10.htm.