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Can full-field color patterns be used to calibrate color decoding on plasma?

post #1 of 31
Thread Starter 
I am using an older Lumagen HDQ video processor that also serves a signal generator for test patterns. I prefer to use the Lumagen's test patterns whenever possible (as opposed to Blu-Ray disc or whatever) because I trust that the source is calibrated correctly and can use it on all of my inputs. However, while the lumagen has IRE window patterns for calibrating grayscale, the only color patterns it has are full fields (as opposed to window patterns).

Since my display is a plasma, I know it has automatic brightness limiting and therefore have never used full-field color patterns for anything up to this point.

However, my question is this: If I measure the full-field 100 IRE white and use that as the 100 IRE measurement, can I then use the full-field color patterns to adjust Y for the primaries and x,y for the secondaries?
post #2 of 31
Quote:
Originally Posted by gremmy View Post

However, my question is this: If I measure the full-field 100 IRE white and use that as the 100 IRE measurement, can I then use the full-field color patterns to adjust Y for the primaries and x,y for the secondaries?

It's a slippery slope your treading on. If I were to give a blanket answer I would say no.

If you want to find out, test it. Do a first run with full windows, and see what the results look like, then do it again with window or APL patterns form the disc and see how different the results are.
post #3 of 31
Thread Starter 
I'll take your word for it.

Now I just need to figure out why the AV HD 709 DVD is giving me different gamma readings than the internal test patterns in the lumagen... Before I can use the color windows I have on disc, I need to figure that bit out.
post #4 of 31
Quote:
Originally Posted by gremmy View Post

I'll take your word for it.

Now I just need to figure out why the AV HD 709 DVD is giving me different gamma readings than the internal test patterns in the lumagen... Before I can use the color windows I have on disc, I need to figure that bit out.

Look at the big Y numbers, they'll likely be the same for some readings, then start diverging. Gamma numbers are all based off of the 100% reading, so if that's different all the gamma numbers will be different. But it may be possible that from 0-80% they are the same then the limiting circuitry could kick in effecting the last two readings, which would give a drastically different gamma curve, event though through 80% it's exactly the same.
post #5 of 31
Thread Starter 
Thanks for the input.

I suspect I have found the problem. It seems I have RGB Full Range (HDMI) set to limited instead of full on the PS3. According to the PS3 documentation, limited outputs 16-235 while full outputs 0-255. What's funny is that I had it set on full previously but it seemed to be clipping information below video black, which seems counter to the documentation. Very strange. I need to look into this further.
post #6 of 31
Thread Starter 
After a little more reading, it seems I may have to do the following on my PS3:

1) Force HDMI Output to RGB
2) Set RGB to full range
post #7 of 31
No don't do that you're trying to pound a square peg into a round hole.

Set you PS3 for YCC w/ superwhite on if you want to see BTB and WTW, for games I believe you only have RGB, use RGB limited.

Those are the correct settings for the PS3. TV's have very incosistent namings for HDMI range settings, but you'll want the one that allows you to see BTB and WTW.

Full range is such a strange name, because it usually means clipping and expanding content, taking content in 16-235 and remapping into 0-255.
post #8 of 31
Quote:
Originally Posted by sotti View Post

No don't do that you're trying to pound a square peg into a round hole.

Set you PS3 for YCC w/ superwhite on if you want to see BTB and WTW, for games I believe you only have RGB, use RGB limited.

Those are the correct settings for the PS3. TV's have very incosistent namings for HDMI range settings, but you'll want the one that allows you to see BTB and WTW.

+1, also RGB output on the PS3 doesn't support WTW and BTB. Other devices like the Xbox 360 do.
post #9 of 31
Thread Starter 
Okay, I will force it to output YCC (who knows what it is outputting now) and set it to output HDMI RGB FULL RANGE, which according to this link is the setting that outputs 0 to 255 (although if I am forcing YCC, am I correct to assume that the RGB full range setting does not matter?)

http://manuals.playstation.net/docum...fullrange.html
post #10 of 31
Quote:
Originally Posted by gremmy View Post

Okay, I will force it to output YCC (who knows what it is outputting now) and set it to output HDMI RGB FULL RANGE, which according to this link is the setting that outputs 0 to 255 (although if I am forcing YCC, am I correct to assume that the RGB full range setting does not matter?)

http://manuals.playstation.net/docum...fullrange.html

no, you should leave RGB Full Range at Limited, full is for PC levels only, not WTW and BTB
post #11 of 31
Quote:
Originally Posted by PlasmaPZ80U View Post

no, you should leave RGB Full Range at Limited, full is for PC levels only, not WTW and BTB

Could you post the complete list of proper settings for the PS3 here so it is all clear. I would be interested in saving that data in my personal calibrations info file for future reference. I know there is a thread on the PS3 in another forum but it would be helpful to have the all the proper settings for the device when used as a BR player.
Thanks!
post #12 of 31
Thread Starter 
After reading these responses, it's more unclear to me than ever why the gamma from my PS3 would yield a different result than the lumagen's internal test patterns... It seems I have it set up correctly... Oh well....
post #13 of 31
Quote:
Originally Posted by airscapes View Post

Could you post the complete list of proper settings for the PS3 here so it is all clear. I would be interested in saving that data in my personal calibrations info file for future reference. I know there is a thread on the PS3 in another forum but it would be helpful to have the all the proper settings for the device when used as a BR player.
Thanks!

http://www.ign.com/articles/2008/12/...s3-for-blu-ray
post #14 of 31
Quote:
Originally Posted by gremmy View Post

After reading these responses, it's more unclear to me than ever why the gamma from my PS3 would yield a different result than the lumagen's internal test patterns... It seems I have it set up correctly... Oh well....

The PS3 should be YCbCr with Superwhite On for movies and RGB Limited for games. RGB Full expands the video range to be used with a PC Monitor and not a TV.

Could you be using the reference patterns on the Lumagen and not the adjustable? I have only used the Mini3D and XS but with those the reference would bypass the CMS settings I believe whereas the PS3 would be using them.
post #15 of 31
Quote:
Originally Posted by airscapes View Post


Could you post the complete list of proper settings for the PS3 here so it is all clear. I would be interested in saving that data in my personal calibrations info file for future reference. I know there is a thread on the PS3 in another forum but it would be helpful to have the all the proper settings for the device when used as a BR player.
Thanks!

Here's my PS3 settings. They yield the best results....for me.

Video Settings: "BD/DVD Video Output Format(HDMI) - Y Pb/Cb Pr/Cr

Display Settings: "RGB Full Range (HDMI) - Limited

"Y Pb/Cb Pr/Cr Super-White (HDMI) - On

"Deep Color Output (HDMI) - off
post #16 of 31
Quote:
Originally Posted by ElectronicTonic View Post

Here's my PS3 settings. They yield the best results....for me.

Video Settings: "BD/DVD Video Output Format(HDMI) - Y Pb/Cb Pr/Cr

Display Settings: "RGB Full Range (HDMI) - Limited

"Y Pb/Cb Pr/Cr Super-White (HDMI) - On

"Deep Color Output (HDMI) - off

I haven't found deep color to have any effect on calibration, but I too leave it off just to be safe.
post #17 of 31
Thread Starter 
Quote:
Originally Posted by Smackrabbit View Post

The PS3 should be YCbCr with Superwhite On for movies and RGB Limited for games. RGB Full expands the video range to be used with a PC Monitor and not a TV.

Could you be using the reference patterns on the Lumagen and not the adjustable? I have only used the Mini3D and XS but with those the reference would bypass the CMS settings I believe whereas the PS3 would be using them.

No, I am using the adjustable lumagen patterns (I know this because I have been measuring changes to the grayscale on the lumagen patterns and can see the color/grayscale changes take effect there).
post #18 of 31
Quote:
Originally Posted by PlasmaPZ80U View Post

I haven't found deep color to have any effect on calibration, but I too leave it off just to be safe.

I have a question about a color error I get, maybe you guys can help?

I calibrate my display( Samsung PN58C8000) with an AccuPel DVG-5000, and an i1Display profiled off an i1Pro via HDMI, using CalMan. I have the AccuPel output: YCbCr 444 @1080p 60Hz.

Here's my issue,
After I'm done, and everything is great. I then connect the PS3, and play AVS HD 709. When I play it at 24Hz I get a color error in red and magenta, but if I play it at 60Hz, everything is fine. Is this normal, is it because the initial calibration is done at 60Hz? It's not a huge issue, I just want to understand what's going on. Sorry to thread jack, but it does kind of go with the topic.

Thanks
post #19 of 31
Quote:
Originally Posted by ElectronicTonic View Post

I have a question about a color error I get, maybe you guys can help?

I calibrate my display( Samsung PN58C8000) with an AccuPel DVG-5000, and an i1Display profiled off an i1Pro via HDMI, using CalMan. I have the AccuPel output: YCbCr 444 @1080p 60Hz.

Here's my issue,
After I'm done, and everything is great. I then connect the PS3, and play AVS HD 709. When I play it at 24Hz I get a color error in red and magenta, but if I play it at 60Hz, everything is fine. Is this normal, is it because the initial calibration is done at 60Hz? It's not a huge issue, I just want to understand what's going on. Sorry to thread jack, but it does kind of go with the topic.

Thanks

yes, the color difference is due to the different refresh rate 24Hz vs. 60Hz

you should calibrate for the refresh rate you intend to use most of the time OR make two separate calibrations if your TV allows this
post #20 of 31
Quote:
Originally Posted by PlasmaPZ80U View Post

yes, the color difference is due to the different refresh rate 24Hz vs. 60Hz

you should calibrate for the refresh rate you intend to use most of the time OR make two separate calibrations if your TV allows this

Thanks, that is what I figured. I calibrate at 1080p 60Hz, because this is what most of my sources are.
post #21 of 31
Other than some weird bug, I don't see why a different refresh rate would change the color performance.

Quote:
Originally Posted by PlasmaPZ80U View Post

yes, the color difference is due to the different refresh rate 24Hz vs. 60Hz

you should calibrate for the refresh rate you intend to use most of the time OR make two separate calibrations if your TV allows this
post #22 of 31
Quote:
Originally Posted by TomHuffman View Post

Other than some weird bug, I don't see why a different refresh rate would change the color performance.

It does happen on plasmas, there was a thread quite a while back that went into detail regarding this (something to do with the decay rate of the phosphors IIRC)

it was related to this thread
post #23 of 31
post #24 of 31
Thread Starter 
Holy Moly I wonder if that's the problem I am seeing.

At first, I as thinking it might have had something to do with the AVS HD 709 DVD being loaded into the wrong color space... The reason why I thought this is kind of hard to explain, but I'll try. First, I noticed that the lumagen menu (which displays as a pop-up on the television screen) appeared to load in two different sizes and resolutions: it was one size and resolution on the PS3 main menu and another when I played back the AVS HD 709 DVD. This made me think, at first, that the DVD might be getting upconverted. Why this would matter I have no idea, since I assume the DVD color patterns are per the rec 709 standard...

So I went back into the PS3 menu and turned off upconversion. And the next time I loaded the DVD, the lumagen menu was no longer a different size/resolution, indicating that the source was no longer being upconverted. At least, that's what it meant to me. But now I am thinking that it might have had something to do with 1080p/24, which I had just turned from on to off.

My lumagen is an older model that supports 1080p/24, but not 1080p/60, so I have the main PS3 menu and options for games set to output 1080i... But if I had 1080p/24 turned ON, I wonder now if the PS3 could be pushing the AVS HD 709 DVD at 1080p/24, resulting in those color errors discussed above....
Clearly I need to do some more tests tonight.
post #25 of 31
Thread Starter 
Well, no matter what I wasn't able to get the PS3 and the Lumagen to measure the same gamma... still not sure what the issue is.

Oh well. Such is life.
post #26 of 31
Quote:
Originally Posted by gremmy View Post

Well, no matter what I wasn't able to get the PS3 and the Lumagen to measure the same gamma... still not sure what the issue is.

Most measurement differences in Y on plasma have to be checked against the idea if the measurement is varying due to Average Picture Level (APL). I thought you said the Lumagen would do full field patterns. Did you compare full field measurements from the two sources? Fields may vary a slight bit in Average Picture Level (APL) from items like text markings, but all else being equal, generally I would expect full field measurements to be very similar. I'm not suggesting that you use fields for calibration, but if you want to compare sources on a display that varies depending on APL then using fields may be a way to get similar patterns. Another way to more easily compare sources is by using a display that has little effect regardless of Average Picture Level, such as an LCD TV with a fixed backlight, but making a comparison on a second display may introduce other potential differences.
post #27 of 31
This thread is about the ability of higher refresh rates to raise the black level of a plasma.

"the faster refresh rate ie 72 or 96hz is causing the increased MLL due to the rate of decay in the phosphors, as they are being excited more frequently per second... Resulting in the phosphors not being able to get back to black before the next frame."

I don't see anything here about effects on color performance.

Quote:
Originally Posted by PlasmaPZ80U View Post

It does happen on plasmas, there was a thread quite a while back that went into detail regarding this (something to do with the decay rate of the phosphors IIRC)

it was related to this thread
post #28 of 31
Quote:
Originally Posted by TomHuffman View Post

This thread is about the ability of higher refresh rates to raise the black level of a plasma.

"the faster refresh rate ie 72 or 96hz is causing the increased MLL due to the rate of decay in the phosphors, as they are being excited more frequently per second... Resulting in the phosphors not being able to get back to black before the next frame."

I don't see anything here about effects on color performance.

http://www.avsforum.com/avs-vb/showt...2&highlight=24
post #29 of 31
This thread discusses differences at the low end of the grayscale (20% and below), gamma, black level, and peak output. The original poster was concerned about gamut errors with red and magenta, which not be affected by these sorts of differences.

I am not saying that this is impossible. I'd just like to see some data to support it.

Quote:
post #30 of 31
Quote:
Originally Posted by TomHuffman View Post

This thread discusses differences at the low end of the grayscale (20% and below), gamma, black level, and peak output. The original poster was concerned about gamut errors with red and magenta, which not be affected by these sorts of differences.

I am not saying that this is impossible. I'd just like to see some data to support it.

I don't have an exact reference, I'm just saying refresh rate on a plasma could be the cause for such differences in color. It could be something else though.
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