# Creating a Rear-Projection, Light Tolerant, Digital CYC



## Paddy (Jun 10, 2017)

Hi Everyone!

My TD has asked if we can afford to create a digital cyc for the next show ... and so the research has begun!
The Problem: 

We have a 40'x20' white cyc with roughly 8' of clearance between it and the back wall. We would like to use rear projection for this solution and still be able to compete with reflected stage lights. We have maybe $35k max for the project and already have computers, software, and cabling, so just need the projectors and lenses. Due to the space requirements, multiple projectors with short throw lenses will be needed.

*Research: *
The Barco lens(EN57) is only compatible with their compact projector types(<=4500 lumens). So that's out.

The Sony lens(VPLL-3003) is only compatible with their lower output projectors(<6000 lumens). So that's out.

The Epson lens(ELPLX01) is only compatible with their G series projectors (<=8500 lumens) and the lower output L series projectors(<=8000 lumens). (Lens is $4750) So that's out.

Christie has the 121-127101-XX lens compatible with DXG1051-Q 10k lumen projector for $6800 (plus the lens for $7700 - ouch!).

The Panasonic lens(DLE-030) fits the PT-DX100ULK 10k lumen projector for $7000(plus the lens for $3600). 

_So, perhaps this one._

At 8' the XGA image size is 15x20ft, the WXGA size is 12x19, and the WUXGA size is 13.3x21.2. Three of these projectors, one CS, SL, and SR on end would produce close to full cyc coverage from 20x35 to 20x39.9. However, this doesn't include edge blending allowances (QLab). The projectors can run on edge to enable this solution but the 'portrait mode' requires a special $1000 lamp set and lasts 1000 hours instead of 3000. Gah! This is my current 'solution' but it needs work. 

*Questions: *
Have you tried any sort of full-stage rear projection solution(and what were your results)? 
What do you recommend? 
Do you think the current proposed solution would work? 
Do you have other ideas for doing this(short of a 200k video wall?)  

Any input you can offer would be greatly appreciated!


----------



## RonHebbard (Jun 11, 2017)

Paddy said:


> Hi Everyone!
> 
> My TD has asked if we can afford to create a digital cyc for the next show ... and so the research has begun!
> The Problem:
> ...


Paging @derekleffew &/or @ruinexplorer Can't one of our pro's help poor @Paddy here? He appears to have done his homework more so than most first posters.
Toodleoo!
Ron Hebbard.


----------



## ruinexplorer (Jun 12, 2017)

Let's see what we can do. When you give the clearance of 8', is this the workable distance or the total distance? As the measurement required is from the lens, you need to calculate the depth of the projector plus the amount of room behind it for exhaust purposes. This can quickly shrink the amount of space available. You can use a first surface mirror to increase the image size, but this will add considerably to the cost and to the complexity of the design. Is this a permanent mounting or do you plan on using these projectors for other purposes (do you want to lock yourself into a single projection design?)? I was trying to help @gafftaper to accomplish a similar set-up and was running into considerable challenges. That is still a work in progress.

We still have some unknowns. Have you tried any rear projection on this cyc? As it is not a material that is intended to transmit an image, it is unknown what the transmittance is and if it is sufficient to a good image. If you have projected an image that you find suitable, do you have measurable results? Most likely you will get better results (fewer required lumens, potentially less expensive lenses) with a front projected image. 

Some things to think about. Do you need to fill the entire cyc with an image? Often there will be a set that excludes a good portion of the cyc, thus reducing the amount that needs to be covered. Do you know what kind of content you want to put on it? With a white cyc, you are going to run into contrast issues with some content. This is almost always an issue when there is a chance to compete with ambient light. But when you are looking to have detailed content that has deep hues, then you will have to up the brightness considerably to compensate. Remember, you cannot project black. You cannot subtract the light on the surface, just overpower it. How far will the audience be from the image? You may be able to play with the resolution a bit depending on how far away they are. Is your budget for rental or purchase? Are you figuring in a maintenance budget along with the purchase (if that is the case)? As soon as you are blending projectors, you also need to consider color calibration between projectors, which may limit the models available to you.

Don't worry, this doesn't mean that this won't work, but it might take a bit more planning.


----------



## gafftaper (Jun 12, 2017)

As @ruinexplorer said I've been trying to find a way to fill a 32' wide screen by rear projection with only 13' between the wall and the screen. I've had him helping me (and he knows a LOT about this stuff) and my local sales guy brought in two regional Panasonic sales reps into my theater to take a look. We could find no way to fully fill the screen with current technology without spending about four times what you want to spend on a very elaborate multiple projector setup that would be insane to tear down and set up. A full high resolution video wall would probably be cheaper. So I'm now starting to look into front projection alternatives, hanging the projector high on the first electric and shooting over the performers. It's not exactly the look I was hoping for, but it will at least work.


----------



## Chan Xiang Ju (Jun 14, 2017)

@Paddy

Barco F90-W13 could be a contender once the 0.28:1 lens is shipping in Quarter 3 2017. There is also gonna be a new ultra short throw lens for the TLD range which works with the HDX series of projectors.

I think Epson also has ultra short throw options available for the new laser phosphor projectors.


----------



## cnnrward (Jun 15, 2017)

I've been using our PT-RZ670 with the ET-DLE030 lens in a top-hung front projection setup hanging near 2nd Electric. In my space, it casts about 35'x20' on our 40'x20' cyc. Our 5th legs cut it off about there. It's not enough to compete against x5 Lustr2 Cycs, but I've been allocating budget for a second set.


----------



## RonHebbard (Jun 15, 2017)

cnnrward said:


> I've been using our PT-RZ670 with the ET-DLE030 lens in a top-hung front projection setup hanging near 2nd Electric. In my space, it casts about 35'x20' on our 40'x20' cyc. Our 5th legs cut it off about there. It's not enough to compete against x5 Lustr2 Cycs, but I've been allocating budget for a second set.


@cnnrward Are you budgeting for a second projector or a second set of cyc lights?
Toodleoo!
Ron Hebbard.


----------



## cnnrward (Jun 15, 2017)

For a second projector.


----------



## Jay Ashworth (Jun 15, 2017)

My snap answer is "make your upstage a rear-projection TV": get a big enough mirror, put the projector on the floor at the back of the cyc, and aim it up into the mirror.

Usually, you do this with a front-surface mirror, and they're fragile, but I suspect your audience is far enough from the cyc that their circles of confusion won't let them pick it up if you use a regular one.


----------

