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#### shawntmartin

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I'm gonna be using an Eiki projector which has the exact same specs as the Sharp XV-Z2000. Its rated at 1200 lumens but Projectorcentral tests showed about 960 in bright mode and 470 in the best theater mode. It will be ceiling mounted about 13 ft from a 92" screen. Sometimes I'm gonna want just enough ambient light to walk around while playing the Wii. What screen gain would suit me best?

#### FLBoy

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At 470 lumens a 92" (diagonal) 16x9 matte white screen with 1.0 gain will give you 18.8 fL, which is more than enough brightness.

#### bravo36

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Can I ask how you got that fL figure? Is there one of your excel programs that does that for you, too?

#### FLBoy

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Quote:
Originally Posted by bravo36 /forum/post/15539115

Can I ask how you got that fL figure? Is there one of your excel programs that does that for you, too?

Sort of. I used the Easy Calc to find the viewing area of the screen in sq ft. Then I applied the following formula.

Foot Lamberts = Projector Lumens / Viewing Area x Screen Gain

470 / 25 x 1 = 18.8

#### shawntmartin

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I'm confused. My 92" screen is 7' x 4.75' and that ends being 33' instead of 25'. So am I at 14 fL. Is that still good on light?

#### FLBoy

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Quote:
Originally Posted by shawntmartin /forum/post/15541871

I'm confused. My 92" screen is 7' x 4.75' and that ends being 33' instead of 25'. So am I at 14 fL. Is that still good on light?

1.47:1 is an unusual AR. Is your screen custom? If your screen is rectangular, your diagonal would have to be about 101.5". You can put these numbers into my Easy Calc to see what Image Size would be for a standard 1.78:1 or 1.33:1 projector. Since neither of these standard ARs will completely fill your screen, you would use Image Size instead of screen viewing area for calculating the screen brightness.

As to your other question, most say 14-16 fL is a good target. Some like to start a bit higher than that to allow for lamp aging. You can go lower if you have excellent light control in your HT.

#### FLBoy

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Ahhh. Now that makes more sense!

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