Originally Posted by microcosm
Although I have noticed that when you move a single projector further away it does give a sense that the brightness has decreased. Presumably that is because each pixel on the projection surface is slightly further apart, giving the illusion of an overall decrease in brightness.
It would follow then, that the type of throw the projector has won't affect the perceived brightness, but moving the projector outside of it's specified throw range will affect the perceived brightness.
(Again, I will cross the streams first thing tomorrow
When you move a projector away from the screen, it DOES get dimmer. As you move it away, the image becomes bigger, and the total light is spread across a bigger area.