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Discussion Starter · #1 ·
I have a D50 with an 80x45 screen. I have it set up now and it is set to fill the width of the 16:9 screen (throw distance per Sony PJcalc if I recall.) What this means is on test patterns that take up mostly the full raster (4:3), the top and bottom overshoot the screen and width is right. I set up my video memories by leaving this pretty much untouched and blanking the overshoot (for 16:9 non-anamorphic sources), squeezing the image height for anamorphic (sized with the Video Essentials 16:9 anamorphic pattern) and for 4:3 material, I use a DTC-100 that is set up for 16:9 out putting grey bars on either side of the image. My question: is this the correct approach with 16:9 screens? I was wondering if I moved it closer, could I use more of the raster height but still be able to stretch the width to fit the screen? I use rear projection (which is amazing, by the way)...my projector is mounted in a room painted flat black behind my viewing room and I have a Draper 1.3 gain high contrast glass screen. One problem I am having is convergence. I used to converge from the front (viewing room) for the center areas and move to the RP room to converge the areas on the top and bottom of the raster that fall above and below the screen. This was fine since the back wall above and below the screen was easy to see from the RP room. Now I have built a rack under my screen that is flush on my viewing side but sticks into the RP room a few feet. It is just under the screen the width of the screen. When I try to converge now, the bottom of the test patterns hits this rack area and of course is out of focus and impossible to converge since the back of the rack is about 3' closer to the projector than the screen above it. Any ideas? I thought I could maybe tilt the projector mount up so that the whole image falls above the rack just for convergence, then put it back in proper position after tweaking is complete. The only problem is my RP room is a few steps down from the main level and has very high ceilings, so the projector is close to 15' in the air! Not very convenient to adjust physically.
 

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mikemav,


Let me start by saying I am not an expert, but I have owned D50 for 2 1/2 years, and learned lot here in that time period.


First of all, I understand that all CRT manufacturers recommend a distance greater than necessary to allow for sloppy installation (the image can be made smaller, but it can't be made larger). As a result, the CRT is not used to its full potential, giving up several performance items, especially a decrease in brightness.


When I checked my installation, the projector had been installed 4 inches further away than specified. I ended up moving it 9 inches closer (i.e. 5 inches closer than PJcalc), and got a brighter picture. The exact distance was determined by looking at the image on tubes (check out this fantastic post from Guy Kuo of Avia fame who will tell you more than you'll ever use http://www.avsforum.com/avs-vb/showt...threadid=98042 ).


I believe that you have taken the correct approach on setting the width for your screen, but I cannot help you on your rear-projection convergence problem!
 

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Discussion Starter · #3 ·
Thanks. I will look into moving it forward. I think about the only thing I can do is tilt the projector so that the overshoot below the 16:9 screen falls on flat wall and not my equipment rack. There is about 5" of space under the screen before the rack starts, so hopefully if I need to tilt it I can do it just enough to allow me to do a full converegence and then put it back where it belongs. Does anyone know if it would work to shift the image vertically without moving the projector, converge, and then shift it back? I kind of thought using shift in the PJ settings may not be the best approach for an accurate convergence.
 
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