Wow, thanks for all the good info. That really helps. I'm discovering that I'm probably not going to be able to get a decent one for under $300. That's what I was shooting for, but it may not be realistic.
I wouldn't totally discount it. My local Staples regularly runs SVGA projectors on sale for around the $400 mark. The nice thing about a place like that is that you can try the projector out and return it if you really don't like it.
Things to remember, especially when buying a "cheap" projector:
- the bulb brightness is only ever going to get dimmer over time, so whatever you buy, if your first thought is "gee, that's not very bright" or "those colors don't look right", then pack it up and return it right away.
- resolution is going to be lower on cheaper projectors (usually SVGA, 800x600). This is generally not an issue unless you want to project something that NEEDS a higher resolution to work. iMovie, for example, refuses to run unless you've got a 1024x768 display.
- cheaper projectors may skimp on the number of inputs, the number of ways you can adjust the image, stuff like that. Again, you may not even care if all you ever do is present in the same place.
Projectors are pretty much commodity items these days, I'd say pretty much any model, any brand will work well for your purpose. If you wanted something for your home theater, well, that's a different situation, but what you want it for (teaching, presentations) is what every projector is designed to do...
Buy from a place that lets you return it, and you'll be fine.
(By the way, with respect to DLP versus LCD - I'm one of those guys that sees rainbows too, but these days the projectors have faster color wheels with multiple segments, so the rainbows are MUCH less noticable now.)
. Use the keystone. It takes to long for me to explain, check google. 