Projection Projection Pro-jection

pjc

Member
Joined
Dec 11, 2006
Hey All,
Some projection advice is needed, and since there is no other place to put this...Lighting seemed most fitting.

I am the head lx in hamilton ontario, and am looking for any suggestions that would help solve the following application for a designer who would like (ideally) do the following:

1. rear projection, screen size 35'x27' (landscape)
2. 20' throw distance

I have questions as basic as:
Are theese even feasable dimensions?
What kind of projector (lamp size)?
What kind of lense?
How many megapixels do the images have to be ideally?
What should the image sizes be?
What kind of program should be used (PC/MAC - Power Point?)

Any help or passing this along to any friends that you might have would be greatly appreciated! The piece is "Blood Brothers."

Thanks.
 

Van

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Wow that a two maybe three projector project. simply a single projector won't do it look at the math for the lumens required alone. the more projectors you use the lower the quality the image can be in the first place. Did a Nike show once with a comprable size screen and throw distance but it took 6 or 8 projectors to overcome the stage lights. What type of Projection ? is it a static image ? If so I'd say invest the rental money in a scenic painter, assuming it's not or you wouldn't even be lookng at projection as an option all I can say is WOW Hope you have a real short run and tech week. Why a rear projection for Blood BrotherS ? isn't that a pretty straight forward straight play ? or am I thinking of the wrong show ?
 

SHARYNF

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Sep 3, 2006
HI Is this a static image where you could use slides or some sort of transparency, or does it need to be video?
To give you an idea, 1700 lumens works for a 12x12 screen in a dark room, so with stage lights you would need quite a bit more lumens. There are some high power 10,000 lumen Panasonic units that you could rent. Some of the really large screen projections that you see for instance in Las Vegas can use hugh super expensive video projectors, OR use film with a high lumen lamp.
What you are really looking for if Ft lamberts which is the actual light emitted from the screen. Rear projection really helps quite a bit.

I would say that no matter what you do you are going to need multiple projectors. There is software to spread the image over the two projectors. You are probably going to still get some distortion and visible overlap or seam in the middle.

With rear projection, make sure you keep the reflected light off the screen, it will help, you will lose some contrast

http://livedesignonline.com/mag/killer_projected_images/

Sharyn
 

pjc

Member
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Dec 11, 2006
Hey thank you all so far for the commentary. In response to Van, the show is the straight play Blood Bros you are thinking of, however the design team wants to do something different, and project approx 40 still images and possbibly one video image.

i am getting the sense that this is clearly a more complicated (technically and economically) then what a small pro-regional theatre can handle.

Anyways, any more advice would be great about and thanks for the links.

Cheers.
 

SHARYNF

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Sep 3, 2006
I have done a lot of projection type work, and don't want you to be scared away from it

Here are some suggestions

Look at dividing the screen into three sections, only use the center section for video, and have a setup with three slide projectors that cover all the screen, area. You can rent higher power slide projectors and the 20 feet will not be a problem, and the level will work quite well. By reducing the size of the video image to just 1/3 of the screen you will increase the brightness since you are then placing the output from the projector lamp on a smaller area. If you absolutely need the height with images, then add another row of projectors above. If you make your image design so that each image has some sort of border it works quite well, Multi projector slide shows were all the rage in the old days, and you can get simple units that will fire off the projectors all in unison

Have your stage lights set up so that there is no spill on the screen, and use rear projection, and it will work fine

Sharyn
 
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Van

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Thanks for the response PJC. I was not critisizing the idea, I love the idea of using multimedia for straight plays and this particular application sounds cool. I like sharyns idea of using slide projectors. I have used them in the past for this kind of presentation. The cool thing is that now days you can pick up slide projectors and wide angle lens for dirt cheap. Just last year a guy was clearing out some old gear and gave me a multi - projector programmable disolve machine. 10 years ago 5-7 thousand dollars worth of gear today it's trash. Run an ad on your local Craigslist or something comprable and I bet you could turn up a ton of projectors. and maybe some equipment like disolvers etc.
 
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Foxinabox10

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Boston, MA
Heck, there may be some at the back of the AV closet at the school.
 

SHARYNF

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Sep 3, 2006
Depending on how much you want to spend
KODAK EKTAGRAPHIC III E 35mm SLIDE PROJECTOR was the standard in its days reliable, and a real work horse they sell for about 40 dollars or so these days

AVL was the main company making dissolve equipment, with Dove as a typical dissolve unit. Some AV company probably has racks for the projectors, dissolve units and programmers all sitting around just wanting to get rid of them.

If you want to get fancy you can get glass mount slides, and you can make mini gobos, interesting designs

Probably none of the "younger generation" has seen one of the large exotic multi projector presentations that were the rage at trade shows, or visitor centers etc.

Only thing to be aware of is that they are some what noisy, but with a bit of creativity and combining some video you can do some pretty neat stuff
Sharyn
 
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pjc

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Dec 11, 2006
Cool, this forum is really quite great considering I just discovered it. The problem to me is still trying to solve the 'friggin' huge' dimensions of the screen - still any thoughts then with the slide projector idea -

1. rear projection, screen size 35'x27' (landscape)
2. 20' throw distance

Thanks, P
 

SHARYNF

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Sep 3, 2006
sorry I thought I made that clear, you need to split the sceen into sections and use multpile slides to cover the area, there is NOTHING that you could get that would cover the entire screen in one shot from 20 feet that is even remotely affordable and would not have massive distortion. So like a typical multi projector slide show of the past the full screen image would be built up from multiple slides, your design to make things simple would be best if each slide had a border and the design had this make sense, so you were not trying to create a seamless image. It is possible to create a close to seamless image, but it is pretty trickey and makes setup very critical
Sharyn
 

SHARYNF

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Sep 3, 2006
It is not just distance, that is bigger than most movie screens in a full blown movie theater, where you have probably close to 200 feet from lens to screen and you have the option of a very high power light source, and a movie theater is ideal conditions with darkness etc.

If you wanted to go really cheap, and ghetto ;-) you could actually use a series of overhead projector that the school probably has around, and use a color ink jet printer to print on clear transparancy images and project them using a bunch of students to change the images ;-)))


Don't laugh OHPs are designed to work close distances, large images, and in lots of ambiant light. You'd be amazed how creative you can get when you need to throw something together at the last minute way out in the boonies
Sharyn
 

Van

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It is not just distance, that is bigger than most movie screens in a full blown movie theater, where you have probably close to 200 feet from lens to screen and you have the option of a very high power light source, and a movie theater is ideal conditions with darkness etc.

If you wanted to go really cheap, and ghetto ;-) you could actually use a series of overhead projector that the school probably has around, and use a color ink jet printer to print on clear transparancy images and project them using a bunch of students to change the images ;-)))


Don't laugh OHPs are designed to work close distances, large images, and in lots of ambiant light. You'd be amazed how creative you can get when you need to throw something together at the last minute way out in the boonies
Sharyn
I agree, I've done worse in the past the important factor with OHPs is to mask the big surfacearea so you don't bleed through you projection surface. I used to love doing the old fashion "psychadelic" projection with a transparency and some oil and food colors, it was toootallly Comsic Man.
Again I agree with Sharyn assesment it's not just can you project an image that big but the question of will you be able to see it once you get it that big. remember the math every square foot you add to a surface area decreases the cnadle power by oi!!wdkdfck12wcw < i don't remember formulas that's what books are for >. :twisted:
 

pjc

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Dec 11, 2006
Hey you great brainstormers... I thank you, and think that we are going to have them re-think the design by way of using 3 ol'fashioned slide projectors (6 for dissolve) and work in panorama. Does anyone have a good projection (lense) calculator. Not sure what kind of size I can get with 20' of throw, but I think the intensity will be better even if one has to compromise with size...as is always the case in life i guess.

Cheers, P.;)
 

SHARYNF

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Sep 3, 2006

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