Using Projections on Stage for Theatre
Projectors in live theatre and events on stage must be bright enough to contend with the stage lights, auditorium lighting, and actors on stage. The many pieces and parts of any system should be considered carefully for reliability and usability in your specific case.
During my time setting up and maintaining projections systems for professional and educational venues, I have learned a lot about the range of systems available, and seen where things often went wrong. I am not a professional scenic or projection designer, nor am I qualified to tell you how to design your projections, so please use this guide mostly as a technical guide for learning the basics of the projection systems used in theaters and auditoriums.
I will start out with some basics and move into the purchasing considerations for some of the equipment necessary. In the interest of keeping things to a reasonable length here, I have linked to other articles which have more info on each topic where relevant.
If you have any questions, please feel free to reach out to me via our contact page, and I will be happy to chat more about any questions you might have!
Projection Terms to Know
I think there are some very important terms to know before going too much further within this guide if you are fairly new to projections. Because I wanted them to have as much detail as I could, I have created a separate article on these terms to ensure they are clearly defined in a useful way.
The Projection Terms page I made includes everything you should need to know, so please read that first if you are unfamiliar with any terms on this page.
Projections Equipment (Hardware and Software)
Projectors
I think everyone knows what a projector is so I don’t feel like I need to define it here, but I will talk a bit about the different types of projectors.
All projectors work in fundamentally the same way, but some projectors accomplish this goal using different sources. The specifics on how each projector create an image is more than I feel is necessary in this guide, so I will instead talk in basic terms.
Some projectors use a lamp similar to a stage light which is filtered and manipulated to create the image. Other projectors use lasers to create an image. Both accomplish the same end goal just using different sources of light. Laser projectors have the advantage of minimal maintenance requirements, as the lasers last a long time, but at an increased cost.
The projectors are obviously the main component of the projection system, however they are only one piece of the system and do not work without the other parts. I have included a guide to choosing the correct projectors further down in this article.
Projector Mounts
There are many different projector mounts available, so I will talk generally about the different types and their uses here. I will link to an article about choosing one specifically within each category later on.
Universal Mounts
These mounts are meant to fit most projectors within a certain size range. They will typically have 3 or 4 arms which can be manipulated to adjust to any mounting pattern. They often have Pan, Tilt, and Yaw adjustments built in for small adjustments.
On this universal mount by Premier Mounts, the arms can be repositioned and attached to any of the slots around the disk, as well as rotated to just about any angle. This allows it to fit almost any mounting pattern on a medium to small projector. This can be screwed to the ceiling directly, or threaded onto a 1-1/2 inch pipe through the large hole on the top.
These are great for fixed ceiling mount positions, but are are limited in the ways they can be mounted. These aren’t well suited to positions where the projector must be mounted vertically, and are often a bit bouncy (if there is any movement of the mounting point, the mount flexes enough to allow movement of the projector). Most universal mounts can only support about 75 lbs.
Rigging Frames
Projector Rigging Frames are ideal for flying positions, mounting the projectors in different orientations, and holding heavy projectors. They are very secure in any mounting position and do not bounce the same way universal mounts do. Most rigging frames allow for 2-3 projectors to be stacked, which is especially helpful for doubling projectors.
This projector rigging frame by Christie Digital allows 3 projectors to be stacked vertically, Includes Pan, Tilt, and Yaw adjustments of the projector within the frame, and holds projectors weighing 100lbs or more. This is just one example of a rigging frame, and they are by no means a universal fit, so be sure to choose a frame that is verified to fit the projector you choose.
Projection Screens
Projection screens come in 2 broad varieties: Front Projection and Rear Projection.
Front Projection screens are basically movie theatre screens, and simply reflect as much of the image back to the audience as possible. There are certain screens meant for high ambient light situations, but they have their limitations and downsides. Front projections in theatre also present the challenge of actors obstructing the projection image by walking in front of it.
Rear Projection screens are much more common on stage, since they allow the image to pass through the screen from the back side. These are usually opaque plastic, and are commonly a grey color to absorb light from the front being selected back to the audience. Projecting from the rear eliminates interference from actors on stage.
Projections can also be used on the existing architecture of a set and don’t require a dedicated screen to project on if there is a wall or other surface which can reflect an image.
Computers and Accessories
Choosing the right computer
Choosing the right computer for your projection setup is a key part of making something that works well. There are a few questions I suggest you ask yourself before starting this search.
- How many projectors will your setup need? This will influence the capability of the computer you purchase. Remember you will need one screen to use as the control screen, so a computer with 3 outputs can only run 2 projectors.
- Mac or PC? Your preferred software will influence this, as well as the price point, ability to upgrade and customize, and lastly your preference of operating system. As of the writing of this article, the most capable Apple computers have a maximum of 4 external displays, with most supporting less. While most off the shelf PC’s are comparable, you are able to upgrade a PC to support more if necessary.
- Will the computer connect to a network wirelessly or through a wired connection? Most production networks are wired networks for reliability, so I would recommend making sure you have some way to connect your computer to the network via hardwire.
- What ports does the computer need? If you plan to connect your projectors with HDMI, are there HDMI ports? (remember HDMI has a max distance of 40-45 feet before signal starts to drop and you must use HDBaseT convertors) Also consider USB, USB-C, SD Card Slots, and Legacy connectors (like VGA).
Accessories
The right computer is important, but choosing the right accessories is almost as important. These things will include a monitor, a keyboard, and a mouse. I also recommend you include some kind of USB Hub, so you can easily connect all of your peripherals and flash drives to upload media to the computer.
If possible, get a fairly large monitor so you plenty of room to run both your projection system, and a files window side by side. I recommend a backlit wireless keyboard and mouse. The keyboard will be used in the dark most of the time, so backlit is a must in my opinion.
For a USB hub, I recommend a hub with multiple kinds of ports, and a few of the more common ones. Multiple USB ports, a USB-C port, and SD Card Slot are all nice to have accessible. This means you have one central place to plug in each flash drive and storage device.
Other Computer Hardware and Equipment for Theatrical Projections
Other hardware to consider including in your setup:
- External Storage for archives and backups
- Network Switch for network communications and projector control
- Cat 5 or Cat 6 cables for connections
- HDBaseT convertors for long signal runs
- Wifi Router for app connections
- KVM Extender for tech table
- HDMI Multiviewer for seeing both normal and backup computer cue lists
- Power strip for computer and hardware
- DMX convertor if necessary
Software
When talking about projection software, I often talk about the “big 3” programs which make up the overwhelming majority of the market when it comes to on stage projections. These are QLab, Watchout, and Isadora.
QLab
QLab is the most common among smaller venues with only a couple of projectors. It’s relatively inexpensive at about $400, and packs a great punch for the price in terms of features. It is easy to learn, user friendly, and extremely reliable. The software is Mac only, with an iPad app to monitor and play cues.
QLab runs all projectors off the main computer, which limits it to the number of outputs your device can support. There are options to output multiple projectors from one output on Mac, but I have found them to be expensive unreliable. In my experience running multiple computers is easier
Isadora
Isadora is another consumer software, with much more interactive and live control abilities than many other software platforms. It currently runs around $550, but when doing anything interactive or fluid, it has much more flexibility. This runs on Mac or windows.
It has many incredible features and is able to support multiple outputs like QLab, really only limited by the computer running it. Isadora also supports live camera feeds, and many other inputs.
A warning about Isadora: Although is a bit more feature rich, I find the software is much less user friendly than QLab. This shouldn’t be a problem if only a few trained people are running the program, but if untrained people need to step in to the program often, you may want to consider another option.
Watchout
Watchout is used in large venues with many projectors, and supports quite literally unlimited outputs. The features of Watchout are a bit limited compared to QLab the last time I used it, but it has been a couple years since I have worked on a setup running it, so it may have gained more features since then.
The System runs one “control” computer which communicates to separate “display” computers which run one or two projectors each. The control computer isn’t actively playing back the media, but rather telling the display computers which video to play and what adjustments to make over a network. This allows the control computer to spread the workload amongst many computers.
The software is a bit pricey and this method requires more computers, which obviously drives the price up a bit as well. If you are running more than 3-4 projectors as one single image, I would recommend using Watchout since it will likely be easier and less expensive than building a computer able to support that many displays at once.
Dowsers
Even when projectors aren’t projecting an image, they will always have a bit of light coming out of them. This “video black” is caused by the source of light which must remain on at a low level to allow proper operation.
This causes problems during a blackout, when the stage is still lit by the projector, allowing the audience to continue to see what is happening on stage. Projector Dowsers are used to block the beam of the projector, and eliminate the spill light when the projector should be off during a blackout. They are a bit expensive, and only a couple of companies make DMX controlled versions.
This dowser is available through any number of sites, and is DMX controlled. Here is a link to the spec page if youre interested in learning more.
Checklist for Equipment
I have created a checklist with everything I would consider buying with a new projection system, which you can download here for free.
