This article was inspired by offers on eBay for home projector construction manuals for around $20 that, on closer inspection, proved to be thoroughly useless.

A film in HDTV resolution (1920x1080 pixels) scaled to the homemade projector: entry-level shelf-bought products don't touch it. Courtesy Artisan/Lightstorm

The result was all the more pleasing: the projector we built convinced even the notorious skeptics at the THG lab in Munich. Despite daylight flooding the room, the luminous efficiency of 3,500 ANSI lumens made it possible to screen DVD films and images onto a white wall. Perfect display quality can be achieved in a completely darkened room. But why not just download our new video (#13)? It will give you an idea of what you can expect from the final product.

The homemade projector is great fun and provides great detail, as a result of its XGA resolution. But it's not just the money you can save that will motivate many users to action - it's the fascination of building, and the ability to select components for optimal picture quality. In our case, the overhead projector (Liesegang OHP 2510) and LCD panel from Iiyama cost just $250. And they don't have to be new devices. Used or cast-off 14" and 15" TFT monitors are widespread nowadays. A good one shouldn't cost more than $150, and the price for a model with non-functioning backlighting will be even lower. Projectors can be picked up at auctions for around $50.

Adding in the cost of small parts such as a fan and tape, you are still well under $300. Considering the result, that's a great deal, especially when you compare the resulting picture quality to a cheapo projector costing at least $500 yet having only SVGA resolution. Another benefit of the homemade projector lies in its use of reasonably-priced halogen lamps (a 400W lamp costs about $30), compared to commercial models using $200 lamps.

What about the downside? Well, the appearance, characterized by a more-or-less chunky projector with a display on top, would certainly not win any design prizes. Also, the LCD panel must be adequately cooled if severe damage is to be avoided. In this context, an annoyingly loud noise may accompany operation. But this is also a well-known problem with low-end projectors.

Nothing to do over the holidays? How about spending a few free days building your own projector? It's certainly a worthy project!