I am looking to buy my first projector . I have read that the downside to DLP is the rainbow effect and headaches after an hour or more viewing for SOME people. Is it that the technology affects some persons eyes and never others; or is it that it depends on the make of the machine. Or another way If I go and look at a DLP machine for a while and find it doesnt affect me, will I get the same non effect on viewing other DLP machines- or could I get the effect if I use another make of DLP machine. Please answer if you know; if you are not sure, please dont speculate. I am having difficulty getting demos of machines. However, if I demo one DLP Id like to know if I can be confident of others giving me the same result. TIA.