Open Forum

We would like to use some projections in the show we are producing next fall. We are in the process of doing our research but, rather than reinvent the wheel, I thought I would start by asking in here. We are not looking to create Broadway quality images but I do want the audience to be able to see the projections! Like most high schools, we are on a VERY limited budget. A nearby high school recently spent over $20K for getting someone to come out and figure out what they need, the equipment, the installation of the equipment and the training with the software. It's quite lovely but is it the only way to go? To give you an idea of how unschooled we are in this area, when we first started thinking about this possibility, we wondered if we could get what we need for somewhere between $700 and $2000. Huge difference, huh?! 

The research we have done thus far has only brought up more questions and is so full of jargon that we are finding it hard to understand. We have found sites that allow us to put in some of our particulars and show us some options for projectors but there is still too much information up in the air for us to know which is best. 

Just in case someone reading is an expert, here are our particulars

• The projector(s) would need to be front mounted (It's less than 3 feet from the back wall to the cyc so rear projections are not possible.
• Projector(s) would need to be mounted on the grid about 24'-26' from the cyc and about 17'-18' over the deck.
• The cyc is 30' wide. I would love to get full width but I would want the image to be at least 25' wide.
• The cyc is about 15' high. Again, I would love to get the full height but I would be willing to lose some height as we often use ground rows and platforms in front of it.
• It's about 27' from the proscenium to the cyc. I can give us a few feet of acting space right in front of the cyc but I would like to know that the actors can get fairly close without the projected images hitting their heads. 

Even though the show we will be doing is fairly "dark" (not be a lot of bright lighting), if we are going to make any kind of investment, we want it to be usable for a variety of types of shows. 

Any insight or suggestions for resources would be greatly appreciated.

Helen Dixon

We would like to use some projections in the show we are producing next fall. We are in the process of doing our research but, rather than reinvent the wheel, I thought I would start by asking in here. We are not looking to create Broadway quality images but I do want the audience to be able to see the projections! Like most high schools, we are on a VERY limited budget. A nearby high school recently spent over $20K for getting someone to come out and figure out what they need, the equipment, the installation of the equipment and the training with the software. It's quite lovely but is it the only way to go? To give you an idea of how unschooled we are in this area, when we first started thinking about this possibility, we wondered if we could get what we need for somewhere between $700 and $2000. Huge difference, huh?! 

The research we have done thus far has only brought up more questions and is so full of jargon that we are finding it hard to understand. We have found sites that allow us to put in some of our particulars and show us some options for projectors but there is still too much information up in the air for us to know which is best. 

Just in case someone reading is an expert, here are our particulars

• The projector(s) would need to be front mounted (It's less than 3 feet from the back wall to the cyc so rear projections are not possible.


• Projector(s) would need to be mounted on the grid about 24'-26' from the cyc and about 17'-18' over the deck.


• The cyc is 30' wide. I would love to get full width but I would want the image to be at least 25' wide.


• The cyc is about 15' high. Again, I would love to get the full height but I would be willing to lose some height as we often use ground rows and platforms in front of it.


• It's about 27' from the proscenium to the cyc. I can give us a few feet of acting space right in front of the cyc but I would like to know that the actors can get fairly close without the projected images hitting their heads. 

Even though the show we will be doing is fairly "dark" (not be a lot of bright lighting), if we are going to make any kind of investment, we want it to be usable for a variety of types of shows. 

Any insight or suggestions for resources would be greatly appreciated.

Helen Dixon

One thing that can save a bundle of money is to rent rather than buy.  Projector technology changes rapidly and almost anything you buy becomes obsolete before the warranty is up.  If purchasing is a possibility, consider discussing this with your school administrators because the availability of good bright projected images can be useful for many types of programs (lectures, films, backgrounds for music programs, etc.) at many venues throughout your school district.  The purchase of projectors for everyone to use can make it a bit more cost-effective.

For this particular application, you should consider projector products that are classified as "Ultra short-throw" or "Extreme short-throw".  These have special lenses that allow the projector to be placed very close to the screen and very off-axis of the screen.  They can be installed either on the floor projecting up at the screen or suspended from the ceiling (or a stage rigging batten -- PLEASE use the proper mounting hardware - don't hang it with bailing wire or ropes over people's heads!).  This placement keeps the actors forward of the screen so they don't get between the light source and the screen and cast shadows (not to mention being blinded).

Most projectors of this type are either XGA (1080 x 768 pixels) or HD (1920 x 1080 pixels).  The higher resolution projectors match the images that come from Blue-Ray players and most modern computers, whereas the low resolution XGA projectors don't (this is not to say you can't use them, they just project images look grainy).

The commonly available projectors, like the Optoma EH320UST or EH320USTI, are about 4,000 lumens brightness, which is OK for a classroom, but still a bit weak (dim) for a large surface like an upstage cyc/screen.  Also, they don't usually focus well if you try to move them way back from the screen to make the image larger.  This means that you will need multiple projectors and they will have to be aligned and set-up so the images blend from one projected image to the next.  You can set up a whole row of these to make a very wide image, and if you place one on the floor and another overhead (inverted), you can blend the top image(s) and the bottom image(s) to create a taller image.  Now comes the rub - you need a an image processor to split the desired back-ground image up across your multiple displays and blend the edges together.  This is why renting is a good deal - this is a very expensive box, and you will need training how to set it up and use it.

As to the projector brightness issue, the math is fairly simple.  You are trying to get an image that is bright enough to be seen by the audience and not washed-out.  You have two factors to consider:

1.  Get rid of any ambient light that spills onto the projection screen.  This means you need to employ good stage lighting practices and shutter-off any light that spills onto the screen (use barn-doors on your fresnels, and the framing shutters on your ellipsiodal lights).  Shallow angle follow spotlights are not going to work well either.

2.  You need a lot of lumens from the projectors.  Your goal is to get 20-40 lumens per square foot onto the screen (brighter is better).  If you have a 9' tall x 16' wide screen, you have 9 x 16 = 144 square feet of image.  If you have a 4,000 lumen projector, then you divide the lumens by the screen area:  4,000 / 144 = 28 lumens per square foot.  This assumes you have a projection screen with a gain of 1X.  If you are using a white muslin cyclorama drop, then your reflected image that the audience perceives is going to be less - maybe 0.6X, so your 28 projected lumens really looks like 28 x 0.6 = 17 lumens per square foot.  Aaggh!

If you move the projector closer to the screen and reduce the image size to 60% of the area (~12'-4" x 7') then your brightness go UP to 4000 / (12.33 x 7) = 46 projected lumens per square foot, and the audience perceives 60% of that, so you get about 46 x 0.6 = 28 lumens per square foot as seen by the audience.

No apologies for the brain-strain here - this is a perfect application of STEAM - Science Technology Engineering Art Math.  Image projection is very predictable if you know the projector brightness, image size, and the projection surface reflectance.