# Basic Information needed about using projectors



## lce0874 (Oct 17, 2012)

I've never used video projectors in a production before but the show I'm designing I'd really like to. I could use some basic info about how to incorportate slides/video into a live show.

Information about setup:
1) Large stage about 40' x 20', screen/scrim would be about the same width/height. Not necessary to fill the scrim, but I'd like to make it pretty big.
2) Theater is equipped with a Strand ShowNet system.
3) They'll be some "trees" permanently in front on either side the screen, so I guess either 1) project into the middle between the trees, (2) sharp angle project behind the trees (distortion issues) (3) rear project, short throw (only 10' behind)
4) Community theater group, so limited budget.

Basic questions:
1) I've used projectors for my day job for powerpoint presentations. Do I have to have a laptop set up backstage with a really long cable going to the projector? How can I control it from the booth (Stand 300 board)? Can I? The space is huge and the booth is probably 150' - 200' away
2) What projectors are good for this size screen (40' x 20')? Multiple projectors?
3) Dousers. Necessary?

Thanks for any input.


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## cpf (Oct 17, 2012)

1) many ways to control it: run n00' of VGA cable so the laptop can be beside you, get a professional grade wireless presentation controller and keep the laptop by the projector, or if you trust the network in the space, use VNC/remote desktop from a computer beside you to control the presentation computer.

3) Depends on your lighting and projector - sometimes "projector black" will be dark enough for your needs, sometimes it won't.


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## JChenault (Oct 17, 2012)

My first question is what are you trying to accomplish with projections? 
Are you expecting a realistic look, or are these abstract looks?
How bright do you want the projection to be?
What are you planning to use for a screen? You mention scrim which is a lousy projection surface for a front projection, and useless for RP ( assuming sharks tooth scrim. )
What's the budget like? 30x40 is a big area. To be bright, video will be spendy whatever you do. There may be other, non video options depending on what you are looking for


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## lce0874 (Oct 17, 2012)

1) Some realistic (fish swimming in water, old fashioned postcards), some abstract (something to give the illusion of falling a long distance (which could probably be done with a scroller?)
2) It's a big house, probably fits 3000 people, so pretty bright.
3) Maybe the video doesn't have to fill the whole screen, have two smaller projectors with two video "areas" and fill in the rest with regular lighting? With the trees it may be like a 20' x 20' unblocked area. What would be a better surface for projection that could also be used for scrim-like purposes where video isn't used (color washes, gobo projections)?


JChenault said:


> My first question is what are you trying to accomplish with projections?
> Are you expecting a realistic look, or are these abstract looks?
> How bright do you want the projection to be?
> What are you planning to use for a screen? You mention scrim which is a lousy projection surface for a front projection, and useless for RP ( assuming sharks tooth scrim. )
> What's the budget like? 30x40 is a big area. To be bright, video will be spendy whatever you do. There may be other, non video options depending on what you are looking for


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## kicknargel (Oct 17, 2012)

Semantics:

I think when you're saying "scrim" you mean "cyc." Scrim is a special open-weave material that is used for bleed-through effects. When properly lit you can see through it to what's behind, and when lit differently it's more-or-less opaque. A cyclorama is essentially a blank backdrop (usually white, light blue, or light grey) That you wash with lighting, often to create a sky, or just an abstract background. 


Cyc is good for projections, scrim is not.


For a 3000 seat house (really?) you're going to have trouble getting good results without big money. If you need just a few looks, you may want to look into layering glass and / or steel gobos in your stage lights. You'll never get realism, but you can get art.


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## museav (Oct 17, 2012)

lce0874 said:


> 3) Maybe the video doesn't have to fill the whole screen, have two smaller projectors with two video "areas" and fill in the rest with regular lighting?


How much light on the 'screen' the projection has to overcome is a potential factor in how bright the projected image needs to be. If you can control the light on the 'screen' then you can get the same image contrast with a lower brightness projected image, but to keep the same image contrast then as the ambient light goes up so must the projector brightness. So you would generally want to keep lighting away from the 'screen' when using projection.

A related factor is how you envision vertically orienting the projected image. If you are thinking projecting a full backdrop down to at or near floor level then not only may it be more difficult to keep light off the screen, much less to limit how much it varies over the screen area, but you can also have to deal with actors and set pieces causing shadows for front projection or with the resulting backlighting from rear projection. That is why you often see projection limited to being above the main performance area.

You may also have to consider the format of the 'screen' and the projected image. The most common projectors provide 4:3 (such as 1024x768), 16:10 (1280x800) or 16:9 (such as 1280x720 or 1920x1080) format images, If you wanted a square projected image you can do that by creating square format content, however you would then not be using the entire projector image area or output. For example, say you wanted a 20'x20' image, a projector would actually create a 26.67' wide by 20' high image area with a 4:3 native format projector (32' wide for 16:10 and 35.56' wide for 16:9 projectors). You could create graphics that only uses the center 20' of that width with black to either side, but the projector is still creating the larger image - including that the projector brightness being spread out over that larger image.

I think John may have been thinking of something like an LED curtain. These can avoid many of the issues of projection and fairly economically provide large images, however the more economical offerings also tend to be large pixel spacings that may be fine for more abstract images while the higher resolution/lower pixel pitch you go for better image quality, the higher the cost.


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## lce0874 (Oct 17, 2012)

Hmm. Food for thought. I was way off on the seat estimate. I'd rather not say by how much, it's pretty embarrassing.


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## JChenault (Oct 17, 2012)

museav said:


> I think John may have been thinking of something like an LED curtain. These can avoid many of the issues of projection and fairly economically provide large images, however the more economical offerings also tend to be large pixel spacings that may be fine for more abstract images while the higher resolution/lower pixel pitch you go for better image quality, the higher the cost.


Actually I had a linnebach projector in mind. But as the OP wants movement, that will not work.
.


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