8mm Forum: Projection screen gain

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Topic: Projection screen gain

Bruce Wright
Expert Film Handler

Posts: 140
From: Denham Springs, La.
Registered: Oct 2011

posted January 06, 2012 05:19 PM

Some screens are rated at 1.0 an others at 1.3 gain.
Enlightenment please. Thanks. Bruce

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Bruce Wright

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted January 06, 2012 08:41 PM

Basically what it comes down to is the directionality of the screen.

As an example matte screens reflect the light projected on them almost in a full hemisphere around the axis of projection.

Lenticular (beaded) screens take that same incident light and concentrate it in a much narrower angle of viewing.

The gain is a measurement of the reflected brightness compared to the brightness incident on the screen surface, both along the axis of projection.

The beaded screen is able to produce a brighter picture on axis, so it is given a higher gain, the matte screen a lower one. The price paid for this bright picture on axis is the sharp drop-off in brightness as you move to the side.

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All I ask is a wide screen and a projector to light her by...

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Pasquale DAlessio
Film God