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Discussion Starter · #1 ·
I have a Samsung LN46A650 that has a CMS with RGB adjustments. I was following this guide: http://www.curtpalme.com/forum/viewtopic.php?t=10457 and it says to adjust the Hue and Saturation without changing the Luminance of each primary and secondary color. I'm finding this hard to do with my RGB style CMS. Is there any tips or tricks on how I can get my colors adjusted without changing the luminance values?


Thanks.
 

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doing it in RGB is a little bit trickier.


Adding any component will increase luminance, removing any component will decrease luminance.


Adding the adjacent channel will shift hue towards that color and slightly desaturate the channel you're adjusting.

Removing an adjacent channel will shift hue away from that color slightly increase saturation for the channel you're adjusting.


Adding values to the channels that should be off will decrease saturation (Red and Blue in the case of Green, Red in the case of Cyan).

Removing values of the channels that should be off will increase saturation of the channel you're adjusting.



So with any RGB change you effect Hue, Saturation and Luminance it's a bit of a balancing act and it'll take a minute to get use to it, but it's very functional (and actually what an HSB does behind the scenes).
 

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Discussion Starter · #3 ·
Thanks for that info... I think I'll have to play around with it till I get the hang of it... I wasn't doing to well yesterday though.



I had another thought...

What if I follow the guide in the opposite way and calibrate the color first? That way I don't have to worry about the luminance of the colors. If I calibrate gray scale after will that give me the correct results? Do I have this totally incorrect and what I'm saying isn't the correct way to do this?
 

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you must adjust the gray scale before ANY gamut adjustment.

Other wise you are just chasing your tail.
 

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That's not quite what it says. Quoting:

While making the adjustments that affect x/y, pay attention to the Y (Luminance) value as well. While only the x/y values should be changing, some displays have poorly implemented colour management systems that also affect the Y value. You may end up getting the correct x/y value and a CIE chart that looks right, but the light output may be completely incorrect which ends up making things worse than before you started! If the Y value starts changing dramatically, go back to whatever settings keep the Y values consistent.
It is not at all uncommon for saturation adjustments to affect luminance. There is a good reason for this. As saturation decreases, the color moves closer to the white point, which will make it brighter.


The problem with CMS implementations that use RGB (Samsungs and Lumagen) is that the human interface doesn't match the perceived change. What I mean is that to desaturate red, you add equal amount of green and blue. However, after doing so the eye doesn't see a greener, bluer color of red. It just sees a less saturated red. Unless your calibration software includes a RGB human interface, CMS adjustment can be a little tricky. Follow these steps:
  • To desaturate a primary color, add equal amounts of the other two primaries.
  • To desaturate a secondary color, add the complimentary color (e.g., add green to magenta, blue to yellow, or red to cyan).
  • To adjust the hue of any color, add the primary that shifts it in the desired direction (e.g., adding red to green will move green closer to yellow).
  • To adjust the luminance of a primary, add or subject itself (e.g., add or subtract red to or from red).
  • To adjust the luminance of a secondary, add or subject in equal amounts the contributing primaries (e.g., to adjust the luminance of yellow, add or subtract red AND green equally)

You may find that desaturating a color affects it luminance. In such cases, just go back and forth between the two until you get the lowest dE you can.

Quote:
Originally Posted by steve6933 /forum/post/19533979


I have a Samsung LN46A650 that has a CMS with RGB adjustments. I was following this guide: http://www.curtpalme.com/forum/viewtopic.php?t=10457 and it says to adjust the Hue and Saturation without changing the Luminance of each primary and secondary color. I'm finding this hard to do with my RGB style CMS. Is there any tips or tricks on how I can get my colors adjusted without changing the luminance values?
 

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Discussion Starter · #6 ·
Thank you for these tips! I'm using ColorHCFR for my calibrations.


Quote:
Originally Posted by TomHuffman /forum/post/19535555
  • To desaturate a primary color, add equal amounts of the other two primaries.
  • To desaturate a secondary color, add the complimentary color (e.g., add green to magenta, blue to yellow, or red to cyan).
  • To adjust the hue of any color, add the primary that shifts it in the desired direction (e.g., adding red to green will move green closer to yellow).
  • To adjust the luminance of a primary, add or subject itself (e.g., add or subtract red to or from red).
  • To adjust the luminance of a secondary, add or subject in equal amounts the contributing primaries (e.g., to adjust the luminance of yellow, add or subtract red AND green equally)
 

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Discussion Starter · #7 ·
The gamut on this TV is smaller than the reference triangle before any calibration is done.


Also, What should settings like Mode, Color Tone, Flesh Tone, Black Adjust, and Gamma start out as? Should they even be used?


Here's what I set...

Mode = Movie

Color Tone = Normal

Flesh Tone = 0

Black Adjust = Off

Gamma = 0


If I had to guess I would say that I should probably be adjusting Gamma and Color Tone, but I'm not really sure.


For Color Tone, I have Warm1, Warm2, Normal, Cool1, and Cool2. I'm not really sure what this control does to the color space or where I should set it before staring calibration.


Any tips would be appreciated.
 

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Undersaturated colors cannot be fixed. All a CMS can do is desaturate oversatured colors.

Quote:
Originally Posted by steve6933 /forum/post/19540931


The gamut on this TV is smaller than the reference triangle before any calibration is done.


Also, What should settings like Mode, Color Tone, Flesh Tone, Black Adjust, and Gamma start out as? Should they even be used?


Here's what I set...

Mode = Movie

Color Tone = Normal

Flesh Tone = 0

Black Adjust = Off

Gamma = 0


If I had to guess I would say that I should probably be adjusting Gamma and Color Tone, but I'm not really sure.


For Color Tone, I have Warm1, Warm2, Normal, Cool1, and Cool2. I'm not really sure what this control does to the color space or where I should set it before staring calibration.


Any tips would be appreciated.
 

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Quote:
Originally Posted by steve6933 /forum/post/19540931


The gamut on this TV is smaller than the reference triangle before any calibration is done.


Also, What should settings like Mode, Color Tone, Flesh Tone, Black Adjust, and Gamma start out as? Should they even be used?


Here's what I set...

Mode = Movie

Color Tone = Normal

Flesh Tone = 0

Black Adjust = Off

Gamma = 0


If I had to guess I would say that I should probably be adjusting Gamma and Color Tone, but I'm not really sure.


For Color Tone, I have Warm1, Warm2, Normal, Cool1, and Cool2. I'm not really sure what this control does to the color space or where I should set it before staring calibration.


Any tips would be appreciated.

You are referring to the Custom color space, right? Auto might be smaller than Custom, which starts out closer to Native. Use Movie/Warm2 (check with meter as Warm1 might be another good option) and Gamma should be whatever is 2.2-2.35 overall (check with meter).
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by PlasmaPZ80U /forum/post/19541633


You are referring to the Custom color space, right? Auto might be smaller than Custom, which starts out closer to Native. Use Movie/Warm2 (check with meter as Warm1 might be another good option) and Gamma should be whatever is 2.2-2.35 overall (check with meter).

I guess when I measured I had it on the Auto color space. When switching to the Custom space, the gamut was larger than the reference (mostly). I was able to tweak it and get it much closer than it was before.


One thing I noticed though... Changing the Color Mode to Warm1/2, didn't change the primary color locations. It only appeared to add red to the whites. Is that what it's supposed to do? If so, why is it suggested to start out with the warm modes as apposed to the normal or cool modes before starting a calibration?
 

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Quote:
Originally Posted by steve6933 /forum/post/19548408


I guess when I measured I had it on the Auto color space. When switching to the Custom space, the gamut was larger than the reference (mostly). I was able to tweak it and get it much closer than it was before.


One thing I noticed though... Changing the Color Mode to Warm1/2, didn't change the primary color locations. It only appeared to add red to the whites. Is that what it's supposed to do? If so, why is it suggested to start out with the warm modes as apposed to the normal or cool modes before starting a calibration?

The color tone of Warm1 or Warm2 is chosen since it's the most accurate starting point for grayscale calibration. CMS calibration is only done once the grayscale is as close to D65 as possible from black to white.
 
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