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The Projectors
Together, the projectors are the most expensive element in the Geowall at $5800. Any DLP projector will work (LCDs won't). Most GeoWall systems have been built with the InFocus LP530; the InFocus LP350s work fine too, although they aren't as bright. We decided to got with the InFocus LP530 models because of size and temperature issues. We purchased from ProjectorPoint.com, who have a special section on their site for the Geowall Consortium. The units cost around $3500 each, but we were able to purchase re-manufactured units for $2900 each. New units have a 3 year warranty, while the re-manufactured units have a 2-year warranty. We had the option to extend this warranty for $150/unit, however we decided against this since 2 years was determined to be enough time for our needs. The re-manufactured units are used, but have all of the pieces that wear out replaced with brand new parts (like the bulb, for example). I should mention that these projectors get hot. When we were using plastic filters, the heat from the projectors actually melted them, causing them to depolarize. It is crucial, therefore, that the projectors be mounted in such a way as to be able to breath. Our projectors included a snap-on accessory that makes it much easier to to plug the cables into the back of the unit, and also let us daisy-chain our monitor to the back of the top projector (we didn't need the video-cable splitter). We put the left eye on the top, and then used that feed to run to the flat panel monitor. Another important element that 'caused us some trouble is that the power cable attaches to the side, rather than the back of the unit. This made it necessary for us to elevate the entire projector out of the tray (because we were using a tray which had been built for a different projector).
Our projectors were slightly off-set in their aspect ratios, which couldn't be tweaked in the projector settings. If we were perfectly lined up horizontally, one output would be taller than the other. It is likely that an exact 3X4 ratio isn't one of the quality-control aspects at the InFocus factory, since it would almost never matter. This, however, turned out to be a small enough problem as to make almost no difference in the results that Geowall produced. These projectors were designed to sit on a table, which means that they project "upwards." If sitting horizontally bottom of the screen is projected almost directly in front of the projector, while the top angles upward. We were told that the ideal positioning for the projectors was about 1/3 of the way from the bottom of the screen; for us that was approximately 4".
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