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Discussion Starter · #1 ·
I like the idea used in this thread and currently have all of the materials needed:

avsforum.com/avs-vb/showthread.php?s=&threadid=290310


I'm limited by the 54" of height the blackout cloth gives me, but how will 4:3 source material look using the 16:9 mode of the X1? A large portion of my projector use will be directv, will I be losing out on much with this method?


In 16:9 mode how many lines of resolution does the X1 yield? Is it enough that 640x480 doesn't have to be converted down?
 

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Don't limit your screen size by the 54" blackout cloth. It is available in 110" widths. I plan to make a 8' X 6' screen. That way I get the biggest 4:3 screen and 16:9 screen. PM me if you want a source for bigger blackout cloth.
 

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Discussion Starter · #3 ·
I've already spent $50 on the cloth and wood, so I think I'll finish this one now and I might make a new one in the future.


One other thing, do I always want the front face of the fabric behind the boards, or can it go either way? I assume the only difference it would make is it allows you to cover the boards in black felt to use as a border.
 

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Discussion Starter · #4 ·
I've reconsidered this and I think I will go with a 8x6 screen. I only have a 7 foot ceiling so that's about all of the height I can get. That gives me a 120" diag. screen, is that still on the safe side for an X1? This is in the basement so there won't be any unwanted light.
 

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96 by 72 inch, you're looking at about 13 lumens / sq foot from your X1 at that size, much too low if you ask me, but hey, it's your decision to make.


Mandarax shoots on 120" diag with an X1, you should see what he says about the image on that size screen.


In the end though, if it makes you happy, who cares what anyone else says. Enjoy;)
 

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I plan a 8' X6' screen but I plan to paint with crt white goo, a gain of 1.6 so I think my lumens per square foot should be fine.
 

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Chances are you are going to be disappointed with the PQ on an 8 x 6 foot screen using Direct TV as your source. I have an 80 x 60 inch screen and Direct TV material looks like crap unless I run it in Native mode--and even then it's not all that great. DVDs, on the other hand, look awesome on my screen. And as Twitchie said with that size screen your picture won't be all that bright.
 

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Quote:
Originally posted by Twitchie
96 by 72 inch, you're looking at about 13 lumens / sq foot from your X1 at that size, much too low if you ask me, but hey, it's your decision to make.


Mandarax shoots on 120" diag with an X1, you should see what he says about the image on that size screen.


In the end though, if it makes you happy, who cares what anyone else says. Enjoy;)
So what's an ideal lumens/sq ft ratio? And what exactly does Mandarax have to say? I'm likely gonna get an X1, and I'm stuck with 80x60 as my min screen size...
 

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Brian, other things you might want to consider in making your decision:


Ideally, your eyes at your sitting position should be about 1/3 of the way up from the bottom of the screen.


The offset for ceiling mounting the projector is 112.2% for a 4:3 aspect ratio. So if you mount the projector 8 inches from the ceiling your 6 foot high screen will only be half a foot or so off the ground to avoid keystoning. That seems uncomfortably low.


Also, how far back are you planning on mounting the projector? And what will your seating distance be? These factors may limit the size of your screen. Check out the projector calulator at Infocus' web site.


The best advice anyone can offer you is to buy the projector first and then determine the optimal size screen for your situation. Good luck and enjoy.


You want to shoot for 16 lamberts (not lumens, sorry) or more for your screen. Hopefully someone else here can post a link to a calculator for determining this.
 

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Found this on the net:


• 1 lumen = 1 candela (cd) steradian = 1 candle


• 1 lambert = (1/ð) * (1 candle per square centimeter) = 0.3183 candles per square centimeter


SYLLABICATION: lam·bert

PRONUNCIATION: lmbrt

NOUN: abbr. L The unit of brightness in the centimeter-gram-second system, equivalent to the brightness of a perfectly diffusing surface that emits or reflects one lumen per square centimeter.



Anyway, everyone will have their own preferences as to how much or little brightness is best for them. Depending on seating distance, you may find that you don't like the resolution of the X1 when the projected image starts to get too big.
 

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so....an X1 at 1100 lumens, projecting onto a 60x80 screen...gives us a rating of .3183 (1100 lumens/30967.68 sq cm) = .0113 lmbrt?


...and half that in "theater" mode, right?
 

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I think, the calculation goes like this: Lamberts = Lumens x Screen gain / Screen area in square feet.


Assume 600 lumens in Film mode on the X1 and a screen gain of 1.0, which I believe is all you are going to get with the High Power when ceiling mounting the projector (not the 2.8 gain that's advertised), and assume a 60 x 80 inch screen (33.33335 sq. ft ).


600 x 1 / 33.33335 = 18 Lamberts


You want to shoot for 16 Lamberts or better.
 
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