Video Asylum

Posted by Chris S. (A) on March 05, 2007 at 08:26:56

In Reply to: 16 FOOT WIDE Movie Screen at home help please posted by mitch4t on March 1, 2007 at 21:00:16:

The key factor is lumens per given area (per sq. ft. in your case). Going to your larger screen dropped that by half, which is a bad thing since you don't have more lumens to compensate for that. Also, using that lens you mentioned will only drop your lumens output even more, so I don't think that will fix it. It is true that less light is lost the closer the projector is to the screen, but I don't think that the 5-20% loss incurred by the lens will be overcome by moving your projector closer. The lens certainly will not overcome the 50% drop in lumens incurred by moving to a much larger screen. You may attempt to try a high-gain screen, however on such a large screen with a low-light projector you will probably have issues with screen uniformity and viewing angles.

Honestly, for a 240" diagonal screen you really do need a "light cannon" projector, which are unfortunately expensive. You also want to be careful about just looking at lumens, because after calibration the light output drops quite a bit from maximum.