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Analog_Alpha
Joined: 17 Jan 2007
Posts: 89
Location: London, Ontario
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| Posted: Wed Dec 12, 2007 7:20 pm Post subject: How much of a bend on a curved screen? |
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Sorry to start another topic, but does anyone know how much of a bend am I allowed to do for a curved 120" wide screen?
Thank you
Chris.
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garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
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| Posted: Wed Dec 12, 2007 7:30 pm Post subject: |
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Depends on the size of your room, how far you sit from the screen, and how wide an "optimum" viewing area you want.
Some people curve it so the screen focuses on one central "sweet spot." That results in too much curvature for most projectors to handle properly, and the brightness drops off rapidly as you get away from the focal point. You can curve it less to spread the light out over a wider viewing area.
Try -Pjackso's spreadsheet for a calculation that takes width of viewing area into account, and shows you exactly how much to bend the screen.
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Analog_Alpha
Joined: 17 Jan 2007
Posts: 89
Location: London, Ontario
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| Posted: Thu Dec 13, 2007 2:50 am Post subject: |
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Someone had just PM me this spreadsheet. Question though, this is all for torus screen. I just want to curve the screen from Left to Right. Would this still apply? Does curving of the screen for CRT change viewing that drastically?
Thank you
Chris.
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26706
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Thu Dec 13, 2007 2:53 am Post subject: |
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Just curious Analog, what material are you using?
_________________
Tech support for nothing
CRT.
HD done right!
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mack1
Joined: 21 Mar 2006
Posts: 494
Location: SARNIA
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garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
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| Posted: Thu Dec 13, 2007 3:51 am Post subject: |
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Yes, you could still use the spreadsheet to figure curve in one dimension. You might get a "vertical line" hotspot that way but it can greatly reduce brightness dropoff at the sides.
Will it help? Depends on your screen material. You should be using a high-gain material for a curve to do any good. I'd say 1.5 at a minimum, 2 or more preferred.
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deronmoped
Joined: 03 Nov 2006
Posts: 1154
Location: San Diego
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| Posted: Mon Jan 28, 2008 4:42 pm Post subject: |
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I went with a 18' radius. I was able to make my NEC 10PG work correctly on it. Recently I switched to a HP.
Deron.
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