# Does a short throw projector exist for this size?



## MercyTech (Nov 3, 2009)

Hi all,
We have budgeted for new projector, and I would love to move it inside the main curtain, and above the actors so that it does not project through them during the performances, especially for the dancers.
I would need it to be mounted approximately 25' above the stage, and 25' from the cyc, which is about 50' wide. Is there an existing projector/lens setup for this short and wide of a throw?
Thanks,
Tim


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## cdub260 (Nov 3, 2009)

I'm not even close to being an expert on projection but I suspect that in order to pull off what you've laid out, that you would need a multi-projector setup with four or more synched projectors, each projecting a portion of the image.


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## TupeloTechie (Nov 3, 2009)

I'm no expert on projection either, but you can do this with one projector. However you are going to need a great deal of keystoning to compensate for such a sharp angle. You can do this without hitting the actors as long as they are around 7-10ft downstage of the cyc, however they should be downstage anyway to avoid spill on your cyc. I'll let other recommend specific projector models, but its not going to be cheap. You are going to want something bright.


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## JohnHartman (Nov 3, 2009)

You are going to have a hard time trying to do that with a single projector with that throw distance. As an example a Christie Roadster with a .73 lens would need 37' 1" to fill a 50' wide cyc. Your issue will be the keystoning because short throw lenses are very sensitive to being even slightly off center. You will likely need to put up an array and run an edge blender system. Possible, just expensive.


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## museav (Nov 4, 2009)

Several issues potentially involved. One is the screen or image height. You make it sound like you want to fill the 50' wide cyc and a 50' wide image would equate to a 28.125' (16:9 format), 31.25' (16:10 format), 37.5' (4:3 format) image height. That could affect both the relative location of the projector to the center and top/bottom of the image and what would be required for that one projector. You'd have to look at the relative vertical orientations and locations to make any assessment on the angles and distances involved, however any of those screen sizes would require a very high output (30,000 to 100,000 lumen or greater) projector or more likely, multiple projectors.

Also consider that the projection path still goes from the projector to the bottom of the image, so while getting the projector closer to the screen and higher above the stage may help in avoiding interference from actors and sets on stage, it will not necessarily eliminate the problem.

Finally, this may not be practical due to the fact that short throw lenses typically relate to little or no lens shift capability and reduced keystone correction. With very short throw lenses the projector really wants to be located on the horizontal and vertical centerline of the image.


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## Esoteric (Nov 5, 2009)

I do a lot of projection work with theaters and churches. First off, the shorter the throw the less keystoning and lens shift you can get. From those stats you are going to need a lot of lens shift. I never use keystoning beyond 3-5 deg off center. Otherwise you get a lot of distortion. In addition you are looking to start at 90 lumens sq/ft and for theater applications I would go with 150 lumens sq/ft or more.

You are looking at an expensive setup.

Mike


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## MercyTech (Feb 8, 2010)

We have changed out set-up somewhat, and now my question changes a bit for our new projector.

I am only concerned with width at this point, which is now at about 40'-45'.
Height is 18', but I can adjust to spill the image onto the stage floor, and crop the images to just fill the cyc.

What I want is to get as close and high as possible (up to 18'), in order to project over the actors head at an angle that will not cast shadows onto the cyc. I know I will have to keystone to make this work, but what projectors/lenses would work best?

Our budget is around 6-7K.

Thanks,
Tim


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## fx120 (Feb 8, 2010)

MercyTech said:


> We have changed out set-up somewhat, and now my question changes a bit for our new projector.
> 
> I am only concerned with width at this point, which is now at about 40'-45'.
> Height is 18', but I can adjust to spill the image onto the stage floor, and crop the images to just fill the cyc.
> ...



Sorry, but it's just not going to happen at your budget. 

Filling a screen that large even from a distance would require a very high brightness projector, something on the order of 25,000+ lumens as Brad mentioned. You're looking at mid-five figure price tags for projectors of that caliber, not to mention the cost of optics which will run you another several thousand dollars.


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## JohnHartman (Feb 9, 2010)

Your issue is still going to be there is not going to be able to pull this off with a single projector with the throw distance given and screen width needed to be filled. The closest I can find will leave you with an unusable dim image at only 35' wide. You are unfortunately looking for something that doesn't quite exist yet, and the only way to do it is not in your budget.


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