Outdoor Projector

[Matt_Tate]

Ok, here's a good one for you...help would be good if there is anyone out there...

 

we are in the process of getting setup with display screens around the school site...very exciting...

we have a new building that has a massive external white wall...the SMT have suggested maybe projecting onto the wall to make use of the space. I think it would look the dogs...but i cant find a way to go about it.

 

my thoughts are that projecting during the day would leave a non visable image, going to rear projection will affect/alter the wall....i thought about short throw projector...but still think this will leave us with a poor image in the day time...

 

any other school been mad enough to do this?

 

Matt

[Andrew_C]

You won't compete with the sun. Just tell manglement to forget it. For a big wall you'd be looking at 10k lumens or more for impact against street lights.

[SteveBentley]

It's been done here, but only worked after dark and needed a really powerful projector that was hired in for the purpose. I wasn't involved so I can't give any specifics.

[Michael]

Interesting idea, but in practice I couldn't see it work well. I also have to ask, what exactly would the school want to display?

[dhicks]

my thoughts are that projecting during the day would leave a non visable image

 

Hmm, can't beat the sun, but could you rig up something involving mirrors to direct the sun's rays through a lens of some kind?...

 

For night-time projection, I know I've seen outdoor cinemas done. I'm guessing your average £600 classroom projector won't produce a very big image, though. Hmm - I wonder how much an old-fashioned (second-hand?) film projector is? The technology must be years old - drive-through cinemas were popular at least half a century ago. Maybe putting your presentation on to a continuous loop of film might be the best option?

 

The cheapest option, I'm guessing, is to go with the kind of lighting used to light up the outside of churches at night. I'm sure there are competing companies that specialise in that kind of thing. I'm guessing it should be relativly easy to add some kind of silhouette image to a light like that (think Batman's bat signal) or maybe even a colour slide (although I'm guessing they might have to be bigger / more heat resistant than normal).

 

--

David Hicks

[mpe]

You won't compete with the sun. Just tell manglement to forget it. For a big wall you'd be looking at 10k lumens or more for impact against street lights.

Actually you can compete with the sun, just that you are better off using an active display. As recently demonstrated on Discovery Channel's "How do they do it?"

One of these does not come cheap even before you consider that you'd be very luck not to need an additional substation in order to plug it in.

[Andrew_C]

Actually you can compete with the sun, just that you are better off using an active display.

He did say projection; yes some of the LED solutions could work, but only if you have the odd £250k spare .

For night-time projection, I know I've seen outdoor cinemas done. I'm guessing your average £600 classroom projector won't produce a very big image, though. Hmm - I wonder how much an old-fashioned (second-hand?) film projector is?

£lots for one that would cope. The really big ones use carbon arc sources and need a skilled operator.

 

I would think a 5.5k projector would be OK on a 20m wide wall if it was proper dark and you have somewhere not too far back to project from. We use one in a fairly light lecture room on a 4m screen and it is OK if the sun isn't directly on the screen (no blinds, never will be).

 

If you can give me an idea of the dimensions involved I know people who would know rather than speculating.

Edited December 3, 2008 by Andrew_C

[crc-ict]

The cheapest option, I'm guessing, is to go with the kind of lighting used to light up the outside of churches at night. I'm sure there are competing companies that specialise in that kind of thing. I'm guessing it should be relativly easy to add some kind of silhouette image to a light like that (think Batman's bat signal) or maybe even a colour slide (although I'm guessing they might have to be bigger / more heat resistant than normal).

 

I've tried to do that with stage lights before and it is MUCH harder than you would imagine. A 'Batman' type mask does absolutely nothing because there is no way to focus. You will always need lenses involved for that kind of thing, certainly to use a slide-type arrangement.

[somabc]

Hmm, can't beat the sun, but could you rig up something involving mirrors to direct the sun's rays through a lens of some kind?...

 

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