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Discussion Starter · #1 ·
I have previously posted about the possibility of increasing my raster after 2000 clock hours and your input was appreciated. Well now I have pretty much analyzed my situation and it comes down to two main options, both with some tradeoffs. I would like some feedback on which path would be the better one to pursue. First, I must report that I increased the raster and feel that I could live with the slight lines due to the wear in my old smaller raster area, should I decide to increase. Yes, I might want to burn them out sometime, but they aren't bad as is and only faintly show up in certain situations (sky for example).


I am sitting back 116.5" from a 79" wide (52" high, but I use only 44.5" of it 95% of the time) screen right now, pretty much on NEC spec. If I would level my PJ (currently tilted a bit), my lense center would sit 30" above screen center for a 14.4 deg angle. This should be 12.2 deg per NEC, so I am 5" too high. Here are my two possible options for change:


1) Buy a 90" wide screen (51" high), which would put me pretty much on the 1.3:1 throw that many seem to like. I have already taken a look at this using my 52" high screen and I sure like the increase in size. Of course I can't see all the width right now, but I got the idea. As I said, the raster wear lines are really not that noticible. I might be able to lower the PJ about 1.5", to reduce the angle to 13.7 deg at the same time. Any lower would begin looking pretty stupid as this is our family room. I have looked at the tubes with this setup and I would be using all the phospor I would dare to use. BTW, PJ tilt could be used but I can't figure out if this helps anything.


2) Or, reduce the drop on my current screen to 44.5" (instead of 52") and drop my PJ 1.5". This combination would put me on NEC spec for throw and angle. I would not be scanning all possible phosphor of course. The change still might throw me into some new phosphor, won't know till everything is done.


Option 1 costs me $ for a new screen, definitely puts me onto some virgin phosphor, and might cause focus and convergence issues due to the close throw and off-spec angle. I sure would have no clue how to preset flapping. But, many of you seem to have gotten around these latter problems. I gain a brighter and larger image, almost like getting a new PJ when you gain that much size. That would be nice after 6 years.


Option 2 is cheap and absolutely by the book. I should be able to get high grade focus and convergence. Probably won't hit new phosphor either. But still takes work and nothing really changes except my screen sits higher and I lose taller image height for viewing digital photo slideshows from my PC.


What would you do and why???
 

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I'm confused...what are the dimensions of your screen? 79x52 or is the 52 just the height from floor to midpoint on the screen?


What is your room setup? Why can't you raise the screen, or change the throw distance?


If I were in your position, I would choose option 3
. 12.2° throw angle, 1.3x throw distance, and if possible a bigger screen. But don't take my opinion over someone more experienced...I'm a nooblet.
 

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Discussion Starter · #3 ·
I have a 79 x 52 screen. bought many years ago before the XG and HDTV. I usually just shoot 44.5" high in the middle of it for 16:9. The screen is in a built in entertainment center and is motorized. Cannot move it higher without tearing it all out, but I do have room for a wider screen. The whole setup was designed for an earlier PJ. The XG is mounted on architectural cross beams that existed in a catherdral ceiling room. The beam height is fixed and if the monster XG is dropped too far below them it will look pretty silly. Hey, life is full of compromises.


Just been playing with watching HD sources 52" high and blanking off sides to fit my current screen. Haven't dialed this in or anything, but it seems like I will need higher contrast shooting larger. I was at 49%, this may take near 60% it seems. Is that normal?
 

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Well you might want to consider a torus screen so you can use higher gain fabric. I run my contrast at 35% and its still very watchable at 25%. Go above 40% and lighter scenes are blinding. This is on an XG1100 by the way.


For a 110" screen, the fabric was around 300$ and the screen cost around 30$ for the wood.


The only negatives are that:

1) You lose corner focus. However, this isn't noticible unless you put up a windows desktop or a test pattern. Nobody really watches the corners anyways.


2) Convergence and geometry are more difficult. I'm having to use nearly -70% bow to get straight horizontal lines!
 
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