homemade rear projection screen

watermelon · Post by **watermelon** » Fri Mar 17, 2006 3:01 pm

im sure weve all seen those projectors made from old tft screens, and ive always wanted to build my own.

I thinking (this is pretty much all theoretical really) about building a coffee table arcade cabinet, but i want the screen to cover most of the table, hopefully around 32". a screen this big isnt neccessary, but why the hell not.

i cant afford to buy a 32" screen of any flavour, but i could build a rear projection screen fairly cheap i rekon. alough i have some concerns

several concerns:
color/picture quality- how good is likely to be in comparrisson to a normal screen?

screen material- i have no idea as of the best material to use. it would be nice to have a one peice glass top to the table and have the area surrunding the screen painted on the back.

distance between the TFT and screen- this can be reduced by the use of mirrors , but i have no idea how tall my table would have to be for this to be viable.

Post by **bicostp** » Fri Mar 17, 2006 3:40 pm

Rear projection would not be a good idea for this. Build a front projection system (like a movie theater or a slide projector.) Building a rear-projection box would take up tons of space, adn if you don't use the right material for the screen the image quality will probably be really sucky.

In order to get the 32" picture you want, you will have to have the projector about 5 feet away from the screen, by my guess.

In order to get a good picture, you really should use a real projection screen. Using a big blank white wall is OK, but unless the paint is flat (not glossy or semi-gloss) you'll get reflection unless you set it up properly. (Just pick up a cheap slide show screen at Goodwill or something.) I use my dad's old slide projector screen, and the image is bright and the colors are vibrant. Sometimes we use the living room wall, and it works OK but the colors are more subdued.

Radon199 · Post by **Radon199** » Fri Mar 17, 2006 4:57 pm

I built a Projector for around $300 CAD and now I have a 90-150" TV in my bacement depending on my mood.

Rear projection is doable but it will cost a hell of a lot. A normal front projection screen from a company like Delite can run around $300 but my fake one that works just as well cost around $50. Rear projection screens cost a hell of a lot more and are still nowhere near as good a quality as a front projection screen, theres a reason that projection TVs are so expencive and thats the screen.

joevennix · Post by **joevennix** » Fri Mar 17, 2006 7:55 pm

Yeah... just build a front-projection. Mucho cheapero. *Mexican hat dance*

XPCportables · Post by **XPCportables** » Sat Mar 18, 2006 11:56 pm

if you are going to spend that much on it why don't you just buy one of these
Link

joevennix · Post by **joevennix** » Sun Mar 19, 2006 1:34 am

You get what you pay for most likely...

Electric Rain · Post by **Electric Rain** » Sun Mar 19, 2006 5:17 am

Yeah, trust me. You probably don't want that projector. The best quality video it supports is S-video. No component, no RGB, no VGA... nothing. If all you want is a big screen, then it would probably work for you. But if you want a decent picture by any means, get a projector with higher quality video inputs.

totokan · Post by **totokan** » Sun Mar 19, 2006 10:35 am

Those instructions are free on the web, as well. It involves a magnifying glass, a TV, and cardboard.

Radon199 · Post by **Radon199** » Sun Mar 19, 2006 11:41 am

Don't do that one, its total crap (as I did it for my first one). Everythings so fuzzy you won't be able to watch anything. The one that really works is a LCD monitor, professional optical parts and a Metal Haloid bulb. Mind you the magnifying glass one costs only $5 but is so bad I can't even beleave I built it.

In fact, if you spend some extra money and use a 17" LCD instead of a 15" one then you can actualy get an 120" HD picture if your LCD has a DVI input.

Harshboy · Post by **Harshboy** » Sun Mar 19, 2006 11:53 am

The easy way to do it:

Buy a 15 in. LCD, and get one of those old projecter things that skools have.

Take the LCD's case off and backlite box off and put it on the projecter. Place a small fan somewhere on the side. Turn projecter on. And you're done

totokan · Post by **totokan** » Sun Mar 19, 2006 7:22 pm

Harshboy, that's what I was going to do. It's a good method, but you need to put the entire setup inside a black box with only a hole for the projecting part, otherwise is sprays too much light. Good to do with a 15" one, though I can't seem to find one.

Radon199 · Post by **Radon199** » Sun Mar 19, 2006 8:29 pm

15" screens are nearly imposible to find, especialy ones that don't have boards hanging over the screen (and thats a lot of them). In all seriousness in a year noones gonna be selling a new 15" LCD, most people will want a 17" LCD, in fact I don't think I could stand a 15" LCD after having this 19" CRT for so long.

Harshboy · Post by **Harshboy** » Sun Mar 19, 2006 8:38 pm

i have a 15 inch LCD, but its my dads...i use a 19 inch LCD