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Discussion Starter · #1 ·
I have a 65" Panasonic plasma (model TC-P65S1) with an IScan Duo with firmware 2.0 (includes CMS). To calibrate, I used the AVCHD disc fed to the Duo via a Sony BDP-N460 blu-ray player. The meter I used was a Eye One Display LT. I used Colorimetre HCFR software. The basic steps I took: set contrast, brightness, Panny service menu gains/cuts, grayscale via the Duo and then the primaries via the Duo and secondaries using the tint control of the Panny.


The attached chc file shows the results are pretty good in terms of gamma, grayscale and color gamut. About the only problem I have is that when I display the basic white level pattern from the AVCHD disc I get pinkish flashing bars. I also get mildly pinkish bright whites in scenes. I've read from the forum that if I turn down the contrast then that fixes the problem - and it does.


Also, if I set RGB in the Duo (at all 11 levels) to zero, each, then I don't get the pink problem. However, my grayscale is not as good compared to when I do adjust the grayscale in the Duo. So, I adjusted the grayscale in the Duo by increasing (mostly) and sometimes decreasing red and blue but left green at 0 because that is what was indicated from the readings. However, one thing I had to do to get 100% white correct was to significantly cut red at the 100% white level in the Duo.


So, my question is there any other way to defeat the pink beast without turning down contrast? Perhaps I just need to scale down all of the RGB levels in the Duo?

 

0311_Calibrated_Full.zip 4.197265625k . file
 

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Quote:
Originally Posted by AtlPaul /forum/post/18298293


So, my question is there any other way to defeat the pink beast without turning down contrast? Perhaps I just need to scale down all of the RGB levels in the Duo?

Lowering the RGB values in unison is essentially the same as lowering your contrast control for that particular stimulus point. The reason that you're seeing pinkish flashing bars on the white flashing bar pattern on the AVS-HD disc is because your display is running out of red at the extreme high end. The background of that pattern is encoded with 254 white. So, when your eyes see the flashing bars against that background, they tend to see the red in the bars which is missing from the background. I suspect if you do a free measure of the 109% white window, you'll see a noticeable drop off of red. You can also bring up a grayscale ramp pattern - look at the above white section of it and then move your contrast control up and down. You should see the luminance response shift as you do this. My guess is that as you increase contrast, you'll see the above white start to take on a cyan color. I would lower contrast until you don't see a noticeable color tinge to the high end of white or you no longer measure a noticeable drop off of red at 109% white. If this results in too dim of an image then you simply need to make a compromise.


hope this helps,



--tom
 

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Quote:
Originally Posted by AtlPaul /forum/post/18298293


I have a 65" Panasonic plasma (model TC-P65S1) with an IScan Duo with firmware 2.0 (includes CMS). To calibrate, I used the AVCHD disc fed to the Duo via a Sony BDP-N460 blu-ray player. The meter I used was a Eye One Display LT. I used Colorimetre HCFR software. The basic steps I took: set contrast, brightness, Panny service menu gains/cuts, grayscale via the Duo and then the primaries via the Duo and secondaries using the tint control of the Panny.


The attached chc file shows the results are pretty good in terms of gamma, grayscale and color gamut. About the only problem I have is that when I display the basic white level pattern from the AVCHD disc I get pinkish flashing bars. I also get mildly pinkish bright whites in scenes. I've read from the forum that if I turn down the contrast then that fixes the problem - and it does.


Also, if I set RGB in the Duo (at all 11 levels) to zero, each, then I don't get the pink problem. However, my grayscale is not as good compared to when I do adjust the grayscale in the Duo. So, I adjusted the grayscale in the Duo by increasing (mostly) and sometimes decreasing red and blue but left green at 0 because that is what was indicated from the readings. However, one thing I had to do to get 100% white correct was to significantly cut red at the 100% white level in the Duo.


So, my question is there any other way to defeat the pink beast without turning down contrast? Perhaps I just need to scale down all of the RGB levels in the Duo?

If you turn off WTW and BTB output, you can hide any color shifts above 100% white (235). You'd still need to make sure 100% is neutral white though. I know my PS3 calls this setting Super-White. If I had to choose between higher contrast and WTW output, I'd definitely go for higher contrast assuming the difference in fL is 5 or more.


On my Samsung LCD, I had two options for getting 40 fL peak white: contrast 100 and backlight 5 w/o WTW or contrast 95 and backlight 6 w/ WTW. The latter option resulted in a brighter black level, greatly lowering the on/off contrast ratio. Giving up WTW output was a minor sacrifice, as very little (if any) content is in that range.
 

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Discussion Starter · #4 ·
Thank you, Tom and Plasma, for your responses as they helped lead me to a solution.

What I did: I measured the 109% white and sure enough it was seriously lacking red with the balanced grayscale settings I was using for 100% white. To get balanced 100% white I had turned-down red significantly which in turn clipped red down to about 72% when measuring 109% white. Apparently that caused the pinkish problem. I'm guessing the hardware is really being pushed at that point and/or the math get squirrelly in the iScan Duo or the tv. My solution was to simply display the 109% white and adjust the 100% white level grayscale settings in the iScan Duo until the RGB was balanced for 109% output. That was easy as all I had to do was set each of RGB to zero in the iScan Duo for 100% white settings. This has the side-effect of throwing off the balance of the actual 100% white level but the benefit of getting rid of the pinkish bright whites. I found this to be a pretty good compromise as I got to keep the higher overall light output and better contrast.


I then redid the grayscale and primaries by adjusting the iScan Duo and tweaked the secondaries with the tv's tint control. While not perfect it's a heck of a lot better than out-of-the-box.


Again, thank you for your feedback as it lead me to a solution and I'm now very pleased with the picture quality.


The latest chc is attached if you're curious...

 

0313_Calibrated_Full.zip 4.09375k . file
 

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