help on project for custom made projector, spherical mirrors.

[Federicomuelas]

Hi Everyone, I tried this thread before but it didn’t go through so here it goes again.
I’m a Physical Computing teacher at the School of Visual Arts in NY and I also have a new media studio based in NY.
I’m doing a public art commission for the University of New Mexico that incorporates a custom made projector, since my field of expertise is computers and electronics I need help designing the optical system, or counseling on how to even start.
To give an idea of the problem...the projected image is 30 feet diameter (circular), the projector is at 31 feet from the center of the screen. The original size of the image to project is about 6 inches in diameter and the projector is 15 feet off-center with the screen, what we were thinking to solve with a spherical mirror (like the ones used on short throw projectors).
We will use a couple of 2000W metal halide lamps as light source.
You have more info of the project at

http://www.federicomuelas.com/blue_flower.

Any ideas on how to even start to working the optical system out? places to look for help? etc?
Thanks!!!
Federico

 

[IRstuff]

No, that was the exterior of the projector housing; the interior will probably be a LOT hotter. Note that the bulbs you mentioned are specified to be fully operable at over 400°C.

I took, I think, 4 kW on something like 3.5ftx6ft of convection area with 10W/m^2-K natural convection coefficient. Very crude, admittedly... That resulted in a 205°C rise above ambient, hence the need for big fans. Based on a still relatively hot 20°C rise (against 49°C ambient), you can only dissipate about 200 W through the housing, which means that the remainder of the bubl power must be removed by blowing air, or a liquid cooling system.

TTFN

FAQ731-376