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gjaky
Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary
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| Posted: Mon Jan 30, 2012 7:35 am Post subject: picture banding on my NEC |
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Yesterday I managed a full setup from zero and I realized that I can't get rid of my picture banding issue on my NEC 6PG xtra. Even with all settings zeroed out with only green on screen I see banding if bright areas on the right edge of the screen (or at least near to it, but only on the right), the machine is floor-front aligned, I don't have point board installed in it. I can live with this but I'm curious about other's opinion. Could this be a timing issue or what?
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6326 Location: Australia
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| Posted: Mon Jan 30, 2012 9:16 am Post subject: |
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What does banding look like?
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26706 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Posted: Mon Jan 30, 2012 9:47 am Post subject: |
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| CasetheCorvetteman wrote: | | What does banding look like? |
Something like this?:
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6326 Location: Australia
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| Posted: Mon Jan 30, 2012 10:33 am Post subject: |
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Should be pretty easy to fix!!!
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gjaky
Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary
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| Posted: Mon Jan 30, 2012 2:35 pm Post subject: |
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Haha guys
I did a little picture to describe. So if the picture is dark and there is some (very)light area in the right edge the picture is lightens up in that band all over horizontally, but if the light are is not in the right edge then no problem
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_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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hansilili
Joined: 09 Mar 2007 Posts: 302 Location: Köln, Germany
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| Posted: Mon Jan 30, 2012 7:54 pm Post subject: |
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sorry, never had that
_________________ HansA, alles andere ist euer Bier!
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amigaman
Joined: 07 Mar 2011 Posts: 50 Location: Missouri, United States
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| Posted: Mon Jan 30, 2012 8:53 pm Post subject: |
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It looks like the image is getting into the clamp circuitry. The projector is using what it thinks is blanking as the black level reference, but it's getting the edge of the image instead.
Try tweaking the image shift (not static alignment) and see if it changes anything. I forget where the adjustment is exactly, but it's next to brightness and contrast in the menu I think. If that doesn't work, the video signal may be shifted too far, or the porches may be too small. I had the same issue with my XG, and shifting the image left or right a little with an HDFury III helped. I only had the problem with 1080p, and I use 1080i primarily now.
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Jeremy112
Joined: 28 Sep 2006 Posts: 2649 Location: Fond du Lac, WI
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| Posted: Mon Jan 30, 2012 9:03 pm Post subject: |
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I think I know what you are describing as I have a similar sounding issue. On my NEC XG the right side of the image is lighter than the left, the blue raster is visible on that side and not on the left.
Messing with blanking changes how it looks, but I do not beleive it is a setting in the projector. I think the image timings/porch settings are off and need adjustment. It is a known thing that NECs do not play nice with source devices, hence why I bought a DVDO VP30 video processor. Since I will be able to adjust the timings, I beleive I should be able to take care of my issues with the raster.
In short, hook it up to a computer, and see how it acts with the signal from that. I'll bet its the timings.
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Jeremy112
Joined: 28 Sep 2006 Posts: 2649 Location: Fond du Lac, WI
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| Posted: Mon Jan 30, 2012 9:06 pm Post subject: |
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I should note that this issue does not affect all NEC projectors. My NEC 9PG Xtra at the same resolution I use from the same source device I use going to my XG does not have any issues at all. The 9PG Xtra I have loves anything I throw at it. I have not tried 1080p but I don't think the tubes would resolve the image very well. 1680x1050 seems to be a good sweet spot for it if you want a nice progressive resolution
_________________ When I'm asking for a Model number, that doesn't mean I'm asking for a nude photo with your number on it
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CasetheCorvetteman
Joined: 09 Nov 2008 Posts: 6326 Location: Australia
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| Posted: Tue Jan 31, 2012 7:10 am Post subject: |
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Oh yes, so what youre saying here is there is a bright item, and horizontally across the screen is a blightened band? My 9PG did that, then the next time i set it up i neutralized the HD Fury 3 side shift and it doesnt do it any more... I never really thought about it much, could barely tell it was there, i could only see it on 1080i
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gjaky
Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary
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| Posted: Tue Jan 31, 2012 7:33 am Post subject: |
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| amigaman wrote: | It looks like the image is getting into the clamp circuitry. The projector is using what it thinks is blanking as the black level reference, but it's getting the edge of the image instead.
Try tweaking the image shift (not static alignment) and see if it changes anything. I forget where the adjustment is exactly, but it's next to brightness and contrast in the menu I think. If that doesn't work, the video signal may be shifted too far, or the porches may be too small. I had the same issue with my XG, and shifting the image left or right a little with an HDFury III helped. I only had the problem with 1080p, and I use 1080i primarily now. |
Thanks! I connect via RGBHV directly to my PC I use 720p@72Hz, increased the front porch and that's solved the problem!
_________________ projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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