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I am determining the measurements for mounting my D50 and had a few questions. In the manual they give the height of the screen (actual screen size) but I am assuming that is for a 4x3 screen. Is there any formula I should be using for 16x9 screen? The distance from the screen to the lens they give for 54" high screen is 107 inches and I currently have the projector sitting 136" away from the screen in my temp. setup for my 96"x54" screen. Any input would be appreciated.

Thanks

Dan
 

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Curt kindly provides a copy of the 5.2 version of PJCalc (although for the D50 calculations I doubt anything has changed).

http://www.curtpalme.com/docs/SonyPJcalcV520.exe


Keep in mind that the distances it provides, much like the pirate code, are more like guidelines than rules. They are often quite conservative and do not make optimal use of the tube face area.


If you have the ability to play with your projector in the space it will be used before you install it permanently, its usually a good idea to see what throw distance really makes sense. Often people run their projectors closer to the screen than the formulae suggest. A shorter throw distance for the same screen size will use more of the phosphor which in turn provides better resolution and light output.


One recommendation is to start at the PJCalc distance. Set a fullscreen image or test pattern and expand the size so that it gets within 1/4 inch of the edge of the tube at the widest point (looking in at the tube face with the contrast down). Then use that with just the green tube (red and blue cut off) to judge how close to the screen the projector should be to get your desired screen size. You'll have to do rough center and edge optical focus as you move it, but you should get a good idea of the practical throw distance.


One trade off is that the optical edge focus does deteriorate at the extrema edges, so some people pull it back a little if they cant get their corners crisp with full tube face utilization. It will also be important to make sure your red and blue tubes can get good mechanical aim with the same raster/image size.


I run my D50 with an 80" wide screen. PJCalc tells me it should be 119 inches from the screen. In practice mine is 103 inches from the screen and I perceive no edge focus issues and the raster is about 1/4 inch from the edge at the widest corners of the trapezoid. So I run mine 16 inches closer than PJCalc suggests.


Be careful not to run the image off the edge or it may damage the tube. And give yourself a little more room or carefully set your blocking if you use the image orbit feature.
 
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