[photo-3d] Silver screens

["John Goodman" <jgood@xxxxxxxx>]

John A. Rupkalvis wrote:

> All silver screens are more directional than their
> counterparts ... If you can, tilt the screen such that the
> brightest reflection is on the center seat... 

I've been pleasantly surprized at how well my home-made 
silver screen works. Mr. Rupkalvis previously posted, most 
helpfully, that "several very light "dusting'" coats applied in 
different directions crossing each other" are called for, however 
I read this a couple of days too late. I have pro-type paint 
spraying equipment, and applied a single heavy coat of 
aluminum-flake oil paint to a sheet of Melamine-surfaced 
plywood.    

I can't tell if the cross-talk is any worse than factory-made silver 
screens, but there is a rather narrow zone of optimum 
brightness, right along the axis of projection. With the projector 
at navel height and centered on the screen, the best view is 
right behind the projector, or else when sitting on the floor in 
front of the projector. Then, any slight darkening of the upper 
portions of the view, due to the lower viewing angle, is not 
usually an aesthetic problem.   

I particularly like the lack of texture offered by a silver screen, 
which increases apparent sharpness, but the depth of focus 
with the projector lenses seems quite narrow. Very slight focus 
adjustments make a lot of difference in terms of viewable 
detail, so it would seem desirable that the screen be in exactly 
the same plane as the projected slide. If the screen were tilted 
out of the plane of the slide, in order to shift the zone of 
brightest reflection to the audience, wouldn't this be at the 
expense of critical focus?      

One thing is certain. Painted silver screens are as fragile as 
front surface mirrors. Any contact whatsoever with the surface 
is apt to be deleterious.

John Goodman