[photo-3d] Re: Looking for a decent/large projection screen

[CanterMike@xxxxxxx]

George writes of his desire for a BIG screen, and asks what we use.  This (of 
course) reminds me of Duggan's tale of the NSA 7x21 foot screen....

At some point in the past, Da-Lite's technique for manufacturing the 
lenticular material (Super Wonder Lite) embossed the ribs (lenticules) onto 
the suface in a different manner that the method they now use.  That process 
limited the screen to no more than 7 feet tall, but as wide as you wanted, 
thus the 21 foot width of the NSA screen.  Today's manufacturing process 
limits the width of the screen but not the height (as they told you).  They 
may not have told you that they offer wider screens in other surfaces, but 
many will have seams (irrelevant to us as those other surfaces do not 
preserve the polarisation that we demand for stereo).

Why are the ribs oriented vertically as opposed to horizontally?  The idea 
behind the lenticular screen is to distribute the light in a more useful 
pattern (compared to a flat screen).  A flat screen will reflect as much 
light up (to the ceiling) and down (to the floor) as it does it does left and 
right (to the audience).  The ribs redirect that "wasted" light back to the 
audience, making it seem brighter (have a higher gain).


Mike Canter