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Discussion Starter · #1 ·
I have a new G15 and am planning its installation.


My 96" wide 16:9 screen is 24 ft from the rear wall - according to the JVC calculator, this screen is slightly too small - However, i believe the Panamorph (ordered) will compress the vertical dimension and possibly increase the throw range I could use to do 16:9 at 96" wide - can anyone help me with the math?


Thanks, TM
 

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Yes, Andy is right - I was having a brain problem when I wrote that the ISCO compresses. The ISCO expands horizontally, so that would make your problem worse, not better.


- Dave
 

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Nstom,

If your rear wall is 24ft away from the screen and the projector will remain in the room, then you will be within the zoom range with a little to spare. The depth of the projector is 14.76 inches (from the front face of the lens to the back of the projector). The position of the lens is the distance you need to use to calculate throw distance. Let us assume that the projector is right up against the rear wall. Based on this, the projectors lens will be located 273.24 inches from the screen. If we divide that number by 3 (full extent of zoom range, maximum tele on the remote)we get a minimum screen width of 91.08 inches, with a zoom capability of producing a 143.8 inch screen with max zoom.


Just one comment, the isco2 will not be available to you in this configuration as it would require you to start with an image that is only 72 inches wide because it horizontally expands the image by a factor of 1.33 to achieve a 16:9 image of 96 inches wide with 54 inches in height.



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Don O


[This message has been edited by Don O'Brien (edited 05-14-2001).]
 

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Discussion Starter · #5 ·
So, if I understand, the Panamorph squeezes vertically - this would put the overly tall 4:3 anamorphically squeezed image into a correctly formatted 19:9 to approximately correct dimension, ie 54" vertically?


So my point was that despite the fact that at full zoom my 4:3 image would slightly overscan in the vertical dimension, the Panamorph may well bring this down enough to allow a full 24' throw (I would really love to get this jet engine mounted through the rear wall!!!)


Sorry to be so thick, but I realize now that I should have made the projector choice BEFORE the screen dimension was set - my fault for being indecisive!


Thanks again, TM
 

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Keep in mind that the panamorph requires that you fill the full width of the screen in a 4:3 frame with a 96" wide image that is 72" high. Subsequently, the image will be compressed down to the correct geometry of 54 inches (1.33334 compression). The smallest width possible at 24ft is 96 inches, for every 3 inches futher away you will produce 1 more inch of image width, and .75 inches of height. So at 24'3" you will have an image of 97"x72.75 inches before the panamorph, and a 97x54.56" after.


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Don O
 

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The Panamorph compresses vertically - it won't let you use a narrower screen if you're already at maximum zoom.


The ISCO lens compresses horizontally - that might do what you want.


- Dave
 

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Dave T is correct.


The Panamorph lens is a triangular prism.


In the horizontal dimension - there is no

refraction - it's a flat piece of glass

horizontally. Therefore, if you are out

of range on the G15's zoom in the horizontal

dimension - the Panamorph will be no help.


As Dave T points out - the ISCO lenses

expand horizontally - and thus could be

a possible solution. You'd have to check

the characteristics of the ISCO lens.


Greg
 

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Well, the ISC lens *expands* horizontally, so it definitely wont do what you want.


How slight is 'slightly too small'? if its < 6 inches or so, I wouldnt worry about it. A little overscan in the black border of the screen is normal.


Andy K.
 
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