[kennedy]

I want to project TV, DVD, and computer images on a large wall on the back of a fairly well-lit room. With projectors ranging from 1000 lumens to 5800 lumens, and the prices ranging similarly, I'm trying to figure out just how much of a projector I need to buy.

Is there anyway to measure ambient light and distances/sizes and compute how much projector is needed?

Since the best prices on projectors are mail order, I'd rather not have to "try them and return them"... or even if that is the ultimate answer, if I can get the first guess closer to right mathematically, that would be helpful.

Thanks.

[boardsurfer]

I can offer just one small experience. A friend of mine has a projector in his studio. It is 2200 lumens and he has it projecting to about a 15 foot diagonal picture. His place is very large, numerous windows and during the day, with all the shades drawn, the picture is still too washed. even with 2200 lumens, it has to be night for a good sharp picture. 2 cents.

edit: on the plus side, Halo absofrickenlutely rocks at 15 feet across!