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DIY High-Quality XGA Projector for ~$300
ranrub writes "Tom's Hardware Guide posted a guide to building your own XGA LCD projector from parts costing under $300. Major components are an overhead projector and a used 15" LCD screen. They even have a movie of the whole project on site! It's quite bigger and noisier than a standard projector, but most of our living rooms look like electronic junkyards anyway, don't they?"
I think these things are really cool, but what still stops me is the bulb cost.
They say the bulbs cost $20-$30 and I can afford that, but how long do the bulbs last? When I searched for Overhead Projector replacement bulbs, I got figures from 30-75 hours. Best case, that's ($20/75hours)= $.26 per hour.
The bulbs for the X1 projector are $299 and last for up to 4000 hours (http://members.shaw.ca/technut/x1faq/#8.2). That is like $.07 per hour.
To me, this really doesn't seem any better off in the long run. Am I missing something?
I built one of these myself a few years ago an it's been running great ever since. I went for a bit sturdier construction so the thing would be portable and I've never had a single problem with it.
more pictures
The whole thing set me back $500 but I'll bet that's mainly due to higher prices back then.
The overhead projector they used in the article is 3500 lumens, but I can speak from their experience that their output isn't that high. LCD panels take a lot of light pushed through them to project a bright image, because the panel is relatively opaque. Overhead projectors are almost completely transparent, so take very little light to produce a bright image. I have a 1991 Proxima Ovation A822C 640x480 data + video LCD overhead projector panel and a 3500 lumen 3M 9200 overhead projector. Showing transparencies, the projector produces a nice bright white color, which looks about the same as a 3500 lumen LCD projector. Throw my LCD panel on it, and the light output drops to under half of the 650 lumen LCD projector that I frequently borrow. I'd guess that the OHP + LCD panel is about equivalent to a 250 lumen LCD projector.
The projector they built looks a lot brighter than mine, probably due to a newer LCD, and not having two layers of protective glass over it, like my LCD panel. However, to make their panel look bright, they tweaked the driver settings. That just changes the color gradients, and doesn't actually make the projector brighter. Even with their tweaks, I doubt that their output breaks 1000 lumens. It would be interesting to get it measured and see what it actually produces. Maybe someone with a lumen meter can fill us all in.
This project really held my interest. Not only could I get a great image for less than 1/3 of the price of a 'real' projector. And I could have more control over it anyway!
It wasn't until the last picture on the last page that I started to lose interest. Notice how the center of the image is far brighter than the edges?
That's entirely expected, if you think about how the overhead projector works. By comparison, I've never seen this on a 'real' projector. Still a nifty idea, but I think I'll splurge on a real one.
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suwain_2