|
|
Post by ronaldus on Nov 10, 2020 9:41:59 GMT -5
Hi Gabor this output to 0-255 is not done in the analog section after the DAC of the MOOME? Anyway, I'll stay with 16-235 if I increase the contrast of the moome in don't have to push the blacks so much in the MARQUEE and I'll get a better (=low noise) black.
Regards,
Ron.
|
|
|
|
Post by gjaky on Nov 11, 2020 8:19:08 GMT -5
Hi Gabor this output to 0-255 is not done in the analog section after the DAC of the MOOME? Anyway, I'll stay with 16-235 if I increase the contrast of the moome in don't have to push the blacks so much in the MARQUEE and I'll get a better (=low noise) black. Regards, Ron. I am pretty sure it is done in the digital domain... |
|
|
|
Post by ronaldus on Nov 15, 2020 5:28:49 GMT -5
Hi Gabor, I increased the contrast pot and it works exactly as you said. I have much more light output and the blacks are OK also. No I can start measuring the greyscale and colors. The reddish effect when increasing the contrast is gone now. What I wonder is the following. I have the VAS test DVD and there is the white clipping test pattern but I never get the white to clip. May be max at 250 or so the white is clipped but not around the 235 as would be the standard. It doesn't change when i increase the contrast pot on the moome and it does not change when I change the contrast on the marquee. The brightness changes of course but the clipping level doesn't. The contrast put on the moome is now at maximum. this is the pattern i use:  Any way the image is much better now. I can now start working on the colors and the sharpness and then it should be ready. The image is so pleasing to look at. Especially with faces and medium shots (here the resolution is sufficient). the contrast is super good. Regards, Ron. |
|
|
|
Post by gjaky on Nov 16, 2020 2:22:09 GMT -5
Hi Gabor, I increased the contrast pot and it works exactly as you said. I have much more light output and the blacks are OK also. No I can start measuring the greyscale and colors. The reddish effect when increasing the contrast is gone now. What I wonder is the following. I have the VAS test DVD and there is the white clipping test pattern but I never get the white to clip. May be max at 250 or so the white is clipped but not around the 235 as would be the standard. It doesn't change when i increase the contrast pot on the moome and it does not change when I change the contrast on the marquee. The brightness changes of course but the clipping level doesn't. The contrast put on the moome is now at maximum. this is the pattern i use: View AttachmentAny way the image is much better now. I can now start working on the colors and the sharpness and then it should be ready. The image is so pleasing to look at. Especially with faces and medium shots (here the resolution is sufficient). the contrast is super good. Regards, Ron. Well we don't know much about the Moome's internal processing, so it might be very possible that it can process higher values than 235 (and it really can, since it can work in 0-255 mode too). As for clipping the projector can have influence on this, as you may know the peak light output can be much higher than the full screen white, therefore test patterns with small windows can be misleading for light output obervations. |
|
|
|
Post by ronaldus on Jan 2, 2021 7:19:26 GMT -5
Hi Everybody, first off all happy New year for everybody! I'm now trying to draw a schematic of the output stage of the moome Internal V3 card for my marquee. I would like to try if i can bypass some filters in the output stage to get a better 1080P resolution. By the way it looks as if the boards was modified. I attached also some pictures of that. If I look at the board I think I found some ferrite beads that I could bypass but I want to have your opinions first. I have indicated them in the attached picture. Regards, Ron the output stage with the ferrite beads  strange things on the board close to some voltage regulator  some parts not populated on the back side of the board.  |
|
|
|
Post by ronaldus on Jan 3, 2021 11:47:37 GMT -5
Me again, I modified the Internal moome card and the results are very good a big improvement. before the modification:  after the modification:  I took the signal directly from the dac output between the ferrite bead and the 75ohm resistor to ground. The ferrite bead connects to a chip that regroups the three channels before sending it to three buffer amps. I guess that this chip is responsible for the contrast and gamma adjustment. I tried first with the bead and the 75ohm removed but the signal was distorted and way too bright. Problem now is that I again have not enough signal to get a sufficient bright image. It's watchable but it misses just a little bit of punch If i could put the contrast at 115% it would be just fine . The switch from 16-235 and 0-255 still works so that's a proof that this is done in the digital domain. I still don't get the same results as in nidi's picture. But the image is way better anyway. I also see the smallest horizontal lines from the test pattern moving to left and right a bit say one second they move and one second they stay still. I'll see if i can shoot a small clip of this. the clip of the shaking: cernbox.cern.ch/index.php/s/GucZUkmsb0fXoEQRegards, Ron. |
|
|
|
Post by gjaky on Jan 4, 2021 17:23:03 GMT -5
Hi Ron, To be honest the bandwidth I see is still far from ideal. For comparison I share a screenshot from my Marquee. The resolution here is 1080i 120Hz, with a pixel clock of 165MHz, so in fact it is slightly higher bandwidth than conventional 1080P 60Hz @148mhz pixel clock. Straight from the PC's VGA output to the Marquee.  |
|
|
|
Post by ronaldus on Jan 6, 2021 16:54:50 GMT -5
Hi All, I tried to take a picture again of the test pattern and it looks a bit better now. I also checked the RGB focus and ASTIG  |
|
