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Discussion Starter #1
I know how a dvd works on my 4:3 pj with the anamorphic lens to squeeze the vert. stretched image to a proper aspect of 16:9.


I've searched but have not found an answer to this question.


Since HD images are broadcast in 16:9 ratio (with no black bars):


How does a satellite HD aspect ratio (16X9) image work on a 4X3 projector that uses the anamorphic lens to fill a 16X9 screen when using DVDs?


Thank you.
 

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Discussion Starter #2
I found an answer at "projectorPeople" (which brings up another question at the bottom).


"Suppose you have a projector containing an XGA panel (1024 pixels wide x 768 pixels/lines of resolution, a 4:3 ratio horiz:vert), with an incoming HDTV video signal (1280 pixels wide x 720 pixels/lines of resolution, a 16:9 ratio). When the incoming image is mapped onto the projector's internal panel, it needs to first be "shrunken" by 20% so that the original 1280-pixel-wide HDTV image will fit onto the 1024-pixel-wide XGA panel. The proportional 20% shrinkage in the vertical dimension will result in an image that no longer contains 768 lines of resolution, but rather 575. This necessary loss of resolution occurs in spite of the fact that an XGA panel has the capacity for 768 lines of resolution, and an HDTV signal consists of "only" 720 lines.


Also note that because the resulting 575-line image is less than the projector's internal panel's 768-line capacity, only 80% of the panel's vertical dimension will be covered with image, and the rest will be blank. Therefore, when centered and projected onto a 4:3-ratio screen, the resulting picture will have the so-called "letterbox" effect, with dark horizontal bars visible both above and below the image*.


*Some projectors will project black in the blank area, while others will actually turn off the pixels for darker black area."


This begs the question:


Is there a scaler that will vert stretch the HD image (similar to anamorphic on a dvd) so that a panamorph can restore it, thus using the whole 4:3 panel?
 
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