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Corleone88
Joined: 09 Dec 2006
Posts: 448
Location: France
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 Link Posted: Mon Jun 08, 2009 7:51 am Post subject: Color adjustment with Lumagen HDQ |
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Hi,
I would like to know what is best to use to adjust primaries :
- the gamut color (adding red, blue and sub green for the green color for example)
or (and ?)
- the color and hue values (colred and huered for example).
After reading posts about it, I am not sure about the ratio for the Y value (also called luminance if I remember correctly):
is it 21% or 25% of the white value for red, 71% or 75% for green and 8% or ??% for blue? What about cyan, magenta and yellow?
My last question is : once the primaries are correct, how to adjust secondaries without too much disturbing the primaries  ?
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Citation4444
Joined: 17 Sep 2008
Posts: 59
Location: North GA Mountains
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| Link Posted: Mon Jun 08, 2009 1:40 pm Post subject: |
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Use the gamut controls available after enabling the service menu.
My experience with the HDQ is that only relatively mild corrections are possible before totally screwing up color decoding. On my DLP projector (with very over-saturated G and R) if I completely correct the primaries the secondaries are screwed up so much there is no way to bring them back in line with the decoding controls. It works ok with small changes to the primaries and then touching up the secondaries. That's all it was meant to do as the HDQ had hardware limitations that didn't allow a full CMS implementation like that in the RadianceXD (and XE). We were lucky to get even that, IMO, as it's not often a manufacturer adds features to mature products like the HDQ. So, even though the CMS has limitations, Lumagen is to be commended for doing it at all.
While the HDQ's CMS leaves something to be desired, its grayscale calibration features are outstanding and work really well.
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Sim2 HT5000e for 2D
Epson 6010 for 3D
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Corleone88
Joined: 09 Dec 2006
Posts: 448
Location: France
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| Link Posted: Mon Jun 08, 2009 2:28 pm Post subject: |
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I have a slight problem with the blue color: if I want to set it with the gamut, I will need to reduce green. How I do that with ADDG ADDR and SUBB?
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Citation4444
Joined: 17 Sep 2008
Posts: 59
Location: North GA Mountains
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| Link Posted: Mon Jun 08, 2009 5:06 pm Post subject: |
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| Corleone88 wrote: | | I have a slight problem with the blue color: if I want to set it with the gamut, I will need to reduce green. How I do that with ADDG ADDR and SUBB? |
You can't. The HDQ CMS (and every other I'm familiar with) require that you start with a gamut wider (outside of) than the gamut you are calibrating to. That's the way they work, by adding the other primaries to move the x,y coordinates in. You can reduce the brightness of the color, but you can't take away. There are some optical methods (filters or coloring the glycol) that might do this, but I'm not familiar enough with them to advise about them.
Are you absolutely sure you have a meter capable of accurately measuring the primaries?? If I recall you have a Display2. I would not trust this meter when making gamut measurements. And, blue is a tough one to measure because the luminance is really low. I would recommend adjusting your grayscale to your liking and leave the primaries alone.
Bob
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Sim2 HT5000e for 2D
Epson 6010 for 3D
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