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HeNkiSdaBro's avatar

How do I project movies onto a white screen from behind?

Asked by HeNkiSdaBro (392 points ) January 12th, 2008

I want to use a screen on stage for my live performances where I can set up a projector behind the curtains and project the movie onto the screen for the audience to watch. How can I accomplish this?

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17 Answers

boydieshere's avatar

Assuming you want the movie projected onto a screen behind you, the easiest way would be to use a projector mounted on the ceiling, actually. If you can get a wireless projector and just a laptop to connect to the projector, it would be the easiest way and you wouldn’t have to worry about blocking it.

gooch's avatar

rear projection requires a special screen

Perchik's avatar

Although gooch is technically correct, the special screen just needs to be extremely thin. We’ve rigged up a pretty simple rear projected movie set up in our apartment. We a white bedsheet stretched tight on a 2×4 frame (that we made). The projector sits about 4 ft behind it on a pile of books. We got our projector off of ebay. The only features the projector needs are the ability to flip the projection, and the ability to get input from your particular source. In our case, we just hook up a laptop, pop in a dvd and it’s good.

Remember that the projection needs to be flipped, aka, if you point it at the wall it should appear backwards. I’m not sure how a DIY setup like ours can be applied to your purpose, but it might help you with some questions.

sndfreQ's avatar

lemme add to perchik and gooch’s suggestion-an in-bedroom screen a/a bedsheet might be fine for an image that’s only 2×4 but what you’re describing for the stage is a much larger image and ‘throw’

The considerations are not only going to be about the special screen type (pro movie houses use a translucent type screen with beaded glass particles embedded in the mesh) for maximizing pickup, but also the projector’s lumen count (loose translation: brightness) and pixel resolution (not as important unless you’re playing higher-than-standard def video (ie higher than DVD resolution).

As gooch mentioned the top-mounting is a bit more cost effective and simpler solution (one other benefit is bot worrying about your roadies and techs walking back behind the scrim/screen into the projection path)-the thing to do is mount the projector either above or below the screen at close distance and try to adjust the keystone settings to bring the image back to rectangular from trapezoidal. Newer projectors are designed for extreme keystoning angles-some upward of 65%!

Then that way you can place the projector out of the way (usually hanging on a lighting truss or behind the drummer position on the floor)

sndfreQ's avatar

one more question as we flush this out-how is this being set up? A solo performance? a band? performance art? What is the level of interactivity with you and others onstage and the imagery on the projection? Or are the images static ‘video backdrops’? a bit more description may help the suggestions…

sndfreQ's avatar

another question-who’s projector? Is it a pro rental or your own-consumer-type or pro projector? The reason I“m asking is that some projectors in the pro-sumer and up levels have add-on lens adapters or actual swappable lenses that will allow for extremely close throws-meaning large image from a short(er) distance.

I know this because I did a rental for a film showcase recently where we rented the screen and projector, and the projector came with a ‘wide angle’ type lens adapter that allowed for a very close throw of about 3 feet from the screen; we projected from a low angle up at the screen and keystoned the bejeezus out of it and got a virtually flat image with no edge distortion! Of course it was a pro-level projector but the rental cost was pretty reasonble…

HeNkiSdaBro's avatar

Thank you all for the informative tips! The performance will be oriented towards a solo performance or maybe involve two people on stage. My brother who is the main act is doing juggling, dancing and acting on stage. I think he wanted motion video and not images on the screen. I will ask my brother and come back to you with more info!

Perchik's avatar

About my response, I guess I wasn’t clear about our frame. It’s made from 2×4s (the lumber) and it’s 8×6ft

breedmitch's avatar

Something else to consider…
I did a show once where the director wanted to attempt sort of the same thing but in tech discovered that all front stage light had to be completely dark for the rear projections to be visible. The actors in front couldn’t be lit because the spots threw ambient light onto the rear projection screen.

HeNkiSdaBro's avatar

good point!

lifeflame's avatar

Did it work out?...

Because I’m interested in trying to back-project something (also for a theatre show) on Chinese calligraphic paper. I’m thinking a HUGE wall to wall paper-wall.
So the paper should be more translucent than a bedsheet…
Also, if I have to rent a special projector, how much would that cost?
(I suppose it might be slightly different in Hong Kong, but it’s good to know approximately.)

steelmarket's avatar

I have used rear projection flexible plastic screening material from Dalite .

It works really well, but it is not cheap!

snotty's avatar

Hi, I also need to back project a video as part of an art work. I need to project it onto something that doesn’t allow the light from the projector bulb to shine in the viewers eyes. I have researched the Da-Tex flexible fabric screen that the last person recommended. It is expensive! Do you know if it lets the projector bulb light shine through? Also, I need to mount it onto a very narrow frame. Do the suppliers also supply frames, have you tried mounting Da-Lite onto them and how difficult was it?! Thanks!

snotty's avatar

Hi All, So, I joined Flutter because I also needed the answer to this question. I have priced Da-Lite and it is ridiculously expensive!!!! I just wanted to let you all know that tracing paper works brilliantly….As opposed to a cotton white sheet-you can see the projector bulb through this. For LifeFlame…If you are intending to use calligraphy paper, it may be possible to make it transparent by rubbing it with oil ie vegetable oil and letting it dry out! Good luck!

KimK's avatar

I have used a white shower curtain that worked great. It cost a buck, so once the evening was over it went into the trash. The plastic was thin enough to project through. For Halloween we put the projector in the garage and projected from the back side and flipped the image. We had a lit fire pit on the front side where everyone hung out. The fire light did not have much affect. Super, professional? No, but it worked well and was cheap.

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