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karoloydi
Joined: 12 Jan 2010
Posts: 8
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 Link Posted: Sun Feb 07, 2010 9:48 pm Post subject: Hit a brick wall with my calibration |
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Heres my calibration results for my LE46A656A LCD.
The grayscale calibration looks quite good. Epspecially the gamma curve. Its really flat compared to my last attempts. I am more concerned about the color calibration.
My biggest problem is that I cant get the red color close to the x=0.640 standard. The highest I can get red is up to 0.620. After that, no matter how many settings I change it doesnt go any higher.
Can someone advise?
Average Gamma 2.22
Contrast 2074:1
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HogPilot
Joined: 21 Jan 2010
Posts: 2383
TV/Projector: Vizio P702ui-B3, Pioneer Elite Pro-151FD & 111FD
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| Link Posted: Sun Feb 07, 2010 10:22 pm Post subject: |
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It looks like all of your primaries are off by a good amount - secondaries look reasonably close. What kind of probe are you using? Also, have you been able to get the Y (luminance values) for your primaries and secondaries relatively close to their target values?
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| ecrabb wrote: | | Curt Palme wrote: | | Interesting, Mac isn't returning my emails. Go figure. |
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garyfritz
Joined: 08 Apr 2006
Posts: 12025
Location: Fort Collins, CO
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| Link Posted: Sun Feb 07, 2010 11:00 pm Post subject: |
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If your primaries are wrong, that's probably the best you can do. (And it's really quite good.) Unless your LCD has a color-management system that lets you tweak your primaries, I'd leave it where it is.
If you have a CMS, then you'd have to tweak the primaries (all 3 could use it) and then start all over again with your grayscale calibration. 
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karoloydi
Joined: 12 Jan 2010
Posts: 8
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| Link Posted: Sun Feb 07, 2010 11:03 pm Post subject: |
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I am using i1 LT. My I managed to get all Y values to target except for red. On the red I I put the Y around 90% accurately, because if I put it 100% accuartely the x value would be even worse.
Do you think I should be more concerned with the Y values than the x and y values?
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HogPilot
Joined: 21 Jan 2010
Posts: 2383
TV/Projector: Vizio P702ui-B3, Pioneer Elite Pro-151FD & 111FD
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| Link Posted: Sun Feb 07, 2010 11:43 pm Post subject: |
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Okay, keep in mind the i1 is not the best tool for calibrating gamut - it works well for greyscale though. So that's something to consider. Just looking at your CIE chart, it looks like it was relatively spot on with its measurements of the primaries/secondaries.
Just to double check, you were trying to adjust the gamut with the CMS controls (Menu>Picture>Detailed Settings>Colour Space>Custom) and not the color/tint controls, correct?
Either way, I dug this up in the LNXXA650 (US equivalent of your set) thread on AVS:
http://www.avsforum.com/avs-vb/showthread.php?p=17467508#post17467508
It appears that the native gamut of this particular model is skewed just as you measured it on yours. Unfortunately you can't do anything about this with the CMS, since a CMS can only be used to shrink, not expand, a display's native gamut. So you're stuck with what you have.
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| ecrabb wrote: | | Curt Palme wrote: | | Interesting, Mac isn't returning my emails. Go figure. |
He's mad at us for making Hog a moderator. He took his ball and went home.
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karoloydi
Joined: 12 Jan 2010
Posts: 8
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| Link Posted: Sun Feb 07, 2010 11:57 pm Post subject: |
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| HogPilot wrote: | Just to double check, you were trying to adjust the gamut with the CMS controls (Menu>Picture>Detailed Settings>Colour Space>Custom) and not the color/tint controls, correct?
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Thats correct.
| HogPilot wrote: | | It appears that the native gamut of this particular model is skewed just as you measured it on yours. Unfortunately you can't do anything about this with the CMS, since a CMS can only be used to shrink, not expand, a display's native gamut. So you're stuck with what you have. |
Thats what I thought.SO do you think that its best to have the Y values 100% perfect and not worry that much about x and y?
Or should I choose to have red's Y 90% perfect so that I can get better x value?
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HogPilot
Joined: 21 Jan 2010
Posts: 2383
TV/Projector: Vizio P702ui-B3, Pioneer Elite Pro-151FD & 111FD
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| Link Posted: Mon Feb 08, 2010 3:23 am Post subject: |
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| karoloydi wrote: | | HogPilot wrote: | | It appears that the native gamut of this particular model is skewed just as you measured it on yours. Unfortunately you can't do anything about this with the CMS, since a CMS can only be used to shrink, not expand, a display's native gamut. So you're stuck with what you have. |
Thats what I thought.SO do you think that its best to have the Y values 100% perfect and not worry that much about x and y?
Or should I choose to have red's Y 90% perfect so that I can get better x value? |
The answer is "it depends." Firstly, if I were you I'd take a look at how things fall when you measure them in u'v' colorspace, because that will show you how you'll perceptually view the deviations from REC709. Make sure you're using dE94 vs dE76 for measuring color deviation as well. Ultimately this is where the "art" of calibration comes in - you'll need to decide how much saturation you're comfortable trading for luminance and which is more apparent to your eyes (in conjunction with continued measurements). You might just have to play with things a bit until you end up with a result that you're happy with both numerically and visually.
_________________
| ecrabb wrote: | | Curt Palme wrote: | | Interesting, Mac isn't returning my emails. Go figure. |
He's mad at us for making Hog a moderator. He took his ball and went home.
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karoloydi
Joined: 12 Jan 2010
Posts: 8
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| Link Posted: Mon Feb 08, 2010 5:45 am Post subject: |
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I am using this tv with my pc. In my graphics card settings there is an option called digital vibrance. I believe this increases the saturation of all colors.
Can I use this, or will it cause any problems?
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garyfritz
Joined: 08 Apr 2006
Posts: 12025
Location: Fort Collins, CO
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| Link Posted: Mon Feb 08, 2010 3:48 pm Post subject: |
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Neither x nor y is intrinsically more important than the other. What's important is the distance (sqrt(x^2+y^2)) from the correct value, and what direction that is from correct. E.g. if your green is X units away from the proper value, it will look worse if it's off in the "yellow" direction than if it's on the "green" line between the correct primary and the central D65 point.
HogPilot may be right that your CMS can't expand the gamut, so you're out of luck for the red primary. But it looks like you could benefit from shifting the green & blue sideways a bit, and maybe the CMS can do that. But really, you're quite close where you are. I'd be tempted to leave it alone unless you really enjoy tweaking with it.
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HogPilot
Joined: 21 Jan 2010
Posts: 2383
TV/Projector: Vizio P702ui-B3, Pioneer Elite Pro-151FD & 111FD
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| Link Posted: Mon Feb 08, 2010 4:11 pm Post subject: |
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| karoloydi wrote: | I am using this tv with my pc. In my graphics card settings there is an option called digital vibrance. I believe this increases the saturation of all colors.
Can I use this, or will it cause any problems? |
You can try this, but it most likely will not fix your problem. From doing some more reading in the AVS thread I linked above, it looks like - for whatever reason - the native gamut of the panel in this model TV is just "skewed" and measures pretty much the same as the measurements you took. Red is of the correct hue but undersaturated, whereas green and blue are rotated towards eachother slightly (incorrect hue) but more or less at the proper saturation level. Turning the digital vibrance on will oversaturate any color with a saturation of less than 100%, but won't increase the saturation of 100% colors as emitted by your display because that's a panel limitation, so any color that goes over the panel's 100% saturation point will simply be clipped at that point. Hopefully that's not too confusing 
Regardless of how well designed a CMS is, it can't exceed the native gamut of the device. If your red is already pegged out at 0,0 in the CMS and it's still understaturated, that's what you're stuck with. I wouldn't worry too much though, the gamut you showed isn't horrendous, and certainly wouldn't be unwatchable either. Unless you're really, really used to looking at proper D65 and REC709 constantly, you probably won't notice the deviation unless you had a side-by-side reference.
_________________
| ecrabb wrote: | | Curt Palme wrote: | | Interesting, Mac isn't returning my emails. Go figure. |
He's mad at us for making Hog a moderator. He took his ball and went home.
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karoloydi
Joined: 12 Jan 2010
Posts: 8
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| Link Posted: Tue Feb 09, 2010 6:17 am Post subject: |
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You re right. I just tried the digital vibrance setting. Nothing changed. Even when I put the digital vibrance to the maximum,the red didnt change.
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