What's the relationship b/t Lumens and Contrast Ratio, when talking about projectors? I know that: Lumens = Candlepower; how bright the picture is Contrast Ratio = diff b/t blackest blacks and brightest whites But how are they inter-related? I've noticed PJs costing $XYZ that have a certain amount of lumens and a specific contrats ratio. Then I've seen PJs costing 2x what the first one cost w/the same lumens but a higher contrast ratio. Can someone explain this to me, please?