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Corleone88
Joined: 09 Dec 2006
Posts: 474
Location: France
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| Posted: Tue Apr 23, 2013 9:48 am Post subject: G2 on Barco |
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Hello,
I would like to understand how works the G2 adjustment with RGB amps (with green led) on Barco.
I have two types of RGB amplifiers: one with green led and the other with no green led.
There are also two procedures to adjust them:
1. adjust the G2 until green led goes off (ABL ON)
2. lum/contrast at 50 + 0IRE picture -> adjust the G2 until the rasters starts glowing (ABL OFF)
I have both types of RGB amps and I follow these two procedures. The problem is that I have two completly different pictures at the end if I display 0IRE on the screen (lum/contrast = 50), and I am wondering why.
The picture with method 1 (amps with green led) is too bright when picture with method 2 (amps without green leds) is ok.
I don't think that my RGB amps with green leds are faulty (maybe one, but 3 is pretty unlikely).
I also have a spare G2 board which gives the same conclusions.
So if someone has an explanation or can tell me how their rasters look like (lum/contrast=50 + 0IRE) after method 1, I am very interested 
Thanks
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Tue Apr 23, 2013 10:13 am Post subject: |
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What happen if you set contrast to 0 (zero) before making procedure 2?
That's how I always made this and I guess it's pretty close to properly calibrated leds.
But actually that doesn't matter much because at the end you use contrast and brightness to set picture.
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Corleone88
Joined: 09 Dec 2006
Posts: 474
Location: France
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| Posted: Tue Apr 23, 2013 12:15 pm Post subject: |
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| Ile wrote: | | What happen if you set contrast to 0 (zero) before making procedure 2? |
I will check this evening, but it doesn't change the fact that the picture looks too bright after procedure 1. It looks strange to me that you have to lower the lum to 35 in order to get a nice picture after doing the procedure 1 (which the usual one).
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Wed Apr 24, 2013 9:31 am Post subject: |
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| Corleone88 wrote: | | it doesn't change the fact that the picture looks too bright after procedure 1. It looks strange to me that you have to lower the lum to 35 in order to get a nice picture after doing the procedure 1 (which the usual one). |
You are right. I thought it was other way around.
Procedure 1 doesn't care sources black level, like procedure 2 does. So I guess difference is caused by elevated black level in source or some external device. (gamma- or hdmi box)
Check sources settings, is there some enchanced black or brightness adjustments?
NTCS setting might also sometimes set black to IRE7.5 level. External gamma or hdmi stripper circuit might also chance things. Hard to say without scoping signals.
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Corleone88
Joined: 09 Dec 2006
Posts: 474
Location: France
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| Posted: Wed Apr 24, 2013 1:03 pm Post subject: |
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If Procedure 1 doesn't care about black levels, what does it care about ?
My source is an OPPO 103 (brightness = 0, everything set to default values) on an input HDMI card (I also tried with HDFury-> same results).
Where is this NTSC setting? In the OPPO?
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Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
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| Posted: Thu Apr 25, 2013 8:08 am Post subject: |
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| Corleone88 wrote: | My source is an OPPO 103 (brightness = 0, everything set to default values) on an input HDMI card (I also tried with HDFury-> same results).
Where is this NTSC setting? In the OPPO? |
Probably not ntsc setting, since it should effect only to ntsc dvd's.
I guess Oppos hdmi is sending Video Level signal (Black=16) at default and hdmi stripper is expecting PC Level signal (Black=0), that will cause too high brightness. Ideally both should be set to RGB Video Level with movie content.
Search how to chance hdmi stripper to take video level signal.
If that is not possible, chance oppos hdmi to pc level. That should correct raised black, but you will lose blacker than black and whiter than white info this way.
Here's some long winded oppo stories.
http://www.avsforum.com/t/1432162/official-oppo-bdp-103-owners-thread/1680
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