Originally Posted by Stereodude
The resolution of the SXRD panels doesn't stop them from doing 1:1 with UHD. The pixels are square. When it's fed UHD (3840x2160) the pixels on the edges aren't used due to the SXRD panels being wider than 16:9. It's basically like the pillarboxing you get when watching 4:3 content on a 16:9 display but to a lesser degree.
Yeah, was one of my guesses (blacking out the ~200 pixels). But it's still not optimal imo. How would you go about framing the picture on your 16:9 screen, would you set the edges at the 4k edge, or the UHD edge. Setting at the 4K edge would create a about 5% border on the sides of your picture which for a 117" screen would be about 5" of screen real-estate that's blacked out on the sides.
Setting it at the UHD edge, would mean you'd possible have picture information outside your screen's masked edges, shouldn't be a problem if you never feed it a 4K image, and stick to UHD, but I know with my current projector and screen, that if a large enough truck has driven past my apartment, the alignment of the screen and projector can go a bit off, setting some picture information outside of the masked part of the screen, and I see some shimmering at the masked bottom or top of my screen, even on Widescreen movies, where the top and bottom are blacked out, it's noticeable.
Not sure how much media there is out there to feed Cinema 4K even, maybe it's something for the ultra high end enthusiast of home cinema, but as these projectors start to come down into more affordable prices, I don't see the draw of a 4096x2160 image over the UHD standard.