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Discussion Starter #1
Hello


I did some measurements with the new ATI driver 7199 and PowerDVD 4

When you touch up the gamma control the brightness and contrast stay until 7 then they change

I did the measurements for Pal and NTSC


Radeon settings


Pal

Gamma 3

Brightness 3%

Contrast 101%


Gamma 7

Brightness 1%

Contrast 103%



NTSC Gamma 3


Brightness 55%

Contrast 95%


Gamma7

Brightness 20%

Contrast 101%


Rob
 

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Rob,

Are those driver settings with PowerDVD settings at default?

What build of PowerDVD is that?

Did you have HA on( I am not sure if that would affect anything)?
 

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Discussion Starter #3
Hello raugustyn


I used WinDVD 2.4DTS and PowerDVD 4 both with HA off and both players at there default settings

My video card is the ATI Radeon 64Mb ViVo


Rob
 

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Rob,


I really don't understand what you have done here. Specifically what do you mean by "When you touch up the gamma control the brightness and contrast stay until 7 then they change" With a scope you measure voltages, so what do you mean by brightness and contrast changing? Please explain.


Regards,

John Moschella
 

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Discussion Starter #5
Hello John


If you touch up the gamma control you adjust the value between 0IRE and 100IRE

If you go to the number 7 from the gamma slider the 0IRE and 100IRE value change

So I calibrate the brightness and contrast again on a gamma setting of 7

If you stay under 7 the brightness and contrast stay the same


Rob
 

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Rob,


I got confused becuase you use brightness and contrast in place of the black level (0 IRE or 0 volts) and white level (100 IRE or 720 mV) voltages. Even though the brightness and contrast effect these voltages they are not really the same thing. For instance, if I raise the brightness it will increase the black level voltage, but I have seen where it also increases the white level voltage to where it may clip. See what I mean. So you should refer to the white and black level votages when you talk about the measurements and brightness and contrast when you talk about the control settings.


So what you are saying is that if the gamma is set to +7 then the black level voltage is no longer 0 and you lower the brightness and adjust the contrast to get the black level back to 0 volts and 700 mV on the white. At gamma +7 what settings for brighness and contrast give you the correct voltages?


John Moschella
 

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Rob:


These values don't look right to me either. I'm not saying you didn't measure properly. What I'm saying is that something got lost in the translation. Could you be specific about attaining 0 IRE in so far as the exact settings in the 7199 overlay tab for brightness, contrast and saturation at gamma 7 (which is where I believe the best shadow detail comes from). I have brightness and contrast set to default with saturation up to 112%. That equates to Cliff Watson's scoped settings for the ATI player some time ago.
 

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Discussion Starter #9
Hello Mike


I leave the color and tint at default

For gamma at 7


Brightness is 1% 0 mV

Contrast 103% 720 mV


Rob
 

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Quote:
Originally posted by Rob Dingen
Hello Mike


I leave the color and tint at default

For gamma at 7


Brightness is 1% 0 mV

Contrast 103% 720 mV


Rob
Rob is this a typo - Brightness 1%?


John
 

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Quote:
Originally posted by John Moschella



Rob is this a typo - Brightness 1%?


John
Probably not, the setting starts at 0.


Jeff
 
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