Originally Posted by cid67
I think you guys may have missed the fact that the screen door like effect he is seeing is diamond shaped and these sets pixels are square in shape.
No, all of the wobulated DLPs have the pizels of the DMD essentially rotated 45°, resulting in the "diamond" shape (they aren't really diamond, but squares turned 45°). They have half the pixel count of a full 1080x1920 frame, and display a frame from two "passes". The second pass is created by a mirror that shifts the output over one pixel, so one "diamond" should display in between two in the next column. So essentially, the pixels tend to overlap. That's why I suggest the wobulation actuator (which shifts the mirror) may not be shifting, because you shouldn't be able to see the individual diamonds, because they'd overlap and prevent the dark lines from being visible. Instead, you should see a zig-zag pattern, but you'd tend to see lines that were brighter, rather than darker, with the brighter portions being the overlap.
Originally Posted by tekkie1958
And if it were taken at the wrong speed?
With the above explanation in mind, if your camera took the picture at a speed that only captured half of the frame (half of a frame is "painted" in 1/120th of a second, so it takes 1/60th of a second for the whole frame to be rendered), then you'd see exactly that... half of the frame. And half of the frame would look exactly like your screen shots. In the next 120th of a second, what you see in your screen shot would be shifted over one pixel column, and the overlapping would remove those lines. So if your camera is taking the shot fast enough that only a partial frame is being captured, the shots show what they should. But if it's 1/60th a second or longer, then it sounds like your TV isn't shifting the image over properly.
EDIT: A picture is worth 1000 words. If you look at figure 4 in this document
, it's a bit easier to understand how it works. The red outlines would represent the first half of the pixels, with the gray outlines representing what would be shown after 1/120th of a second, when the image is shifted over one column, and the second half of the pixels rendered overlapping the 1st half. Your screen shots look like only the red pixels (or only gray, take your pick). If your camera is at a fast enough shutter speed to only capture half of the frame, then that's to be expected. But if the shutter speed is long enough to capture both sub-frames, then the dark lines shouldn't be visible. And if they are, perhaps the mirror isn't "wobulating".