Ok, I can't seem to get a straight answer from anyone on this so hopefully some of ya'll experts here can help.

I'm shopping for my first projector, learning bit by bit.

Since projectors deliver their images in a range of sizes, how do you determine which is the absolute optimum image size to set it to?

Eg, if projector can display an image in the range of 30-300 inches, I'm assuming only one size within that range can produce the best picture possible from that projector.

How do you figure out that number? Is their a method for this, or is it more of a trial and error thing?

Thanks in advance.