ANSI lumens is a brightness measurement that gives you a way to compare overall light output of various display devices on paper. ANSI is a governing standard that helps to insure that youíre comparing apples to apples between different manufacturers so you wonít be misled by claims made from a ìmore forgivingî standard. If the manufacturer claims ì1000 ANSI lumensî, then they must be able to reproduce that measurement with any projector off their ìshelfî, to the exact standards set forth by the ANSI requirements. It is an incentive to ìplay fairî.