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Author Topic: Issue with white point temperature Eizo CG243 and ColorNavigator?  (Read 3930 times)

olje

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I have a dual display setup with Eizo FS2402 and CG243.

The FS2402 is calibrated using Spyder3Elite v4 and CG243 with the Colornavigator v6
Graphics is Nvidia GTX580 using double DVI
Windows 7 64 bit.

Calibration target:
5000K
80Cd white point
minimum black point
Gamma 2.2
to achieve display-print matching with my Epson3880

The FS2402 calibrates well with an accurate white point of 5000K+-30K, as verified with the colorimeter measurement tool in Spyder3Elite software.
 
In the Spyder Elite software the CG243 is non-calibrated and user profiles turned off in the Windows color management dialogue.
 
The CG243 calibrates using the Colornavigator6 and the calibration report indicates an error in the white point of -3Kelvin
 
When looking at the screen it is warmer than the FS2402 and when measured with the same colorimeter tool from Spyder Elite it confirms a white point of 4660K.
 
If the profile is manually adjusted in the Colornavigator 6 software then the CG243 matches the print output for light skin tones, but not as first calibrated.
 
I do not understand where this CG243 calibration goes wrong. Could there be anything disturbing in the LUT on the graphics board for the CG243 even though non-calibrated? Or do you have any other ideas and suggestions?

/O
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Czornyj

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #1 on: April 08, 2012, 09:07:36 am »

ColorNavigator has corection matrices for combinations of CG backlight spectra and bunch of standard sensors - that may cause the difference between Spyder profiling software measurement.

There's also a visual difference between wide gamut CCFL display and standard gamut CCFL display.

From my experience - D50 calibrated display is usually too warm when compared with pigment print in a daylight, I get better a match at ~D65 (depending on OBA content in paper). In practice we don't need to achieve a match with D50 white point, but rather a match with some paper illuminated with daylight or other light source. So it's a spectral reflectance of certain paper in certain viewing condition what really matters, not D50.

All in all - I wouldn't take care about the difference, and found a target that gives a good visual match with print.
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Marcin Kałuża | [URL=http://zarzadzaniebarwa

olje

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #2 on: April 08, 2012, 12:00:07 pm »

Thanks a lot for the info,

I may have misunderstood your answer, but:

One thing I do not understand is why the calibration result as given by the details of the Colornavigator, does not match the measured values off the screen of the CG243. The calibration result says 4997K from the Colornavigator and as measured by the Elite software it is 4660K.

I was surprised to find that the Elite software is better in calibrating the very inexpensive display FS2402 to the right white point, than the Colornavigator is to calibrate the expensive display CG243 to the same white point.

The manually corrected profile by the Colornavigator measured as 5350K approximately and with the Spyder3 Elite software measured as 5000K approximately. The manually adjusted profile looks the same as the other display and matches the printed photos in skin tone when viewed with a D50 light source.

Would you have any ideas to this?
The same sensor is used for both displays, Spyder3.

/Ola
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Czornyj

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #3 on: April 08, 2012, 12:37:52 pm »

Spyder3Elite software has no correction matrix for Spyder3 colorimeter and wide gamut display, while ColorNavigator corrects Spyder3 measurements on wide gamut CG243 - that's why there's a difference in reported white point CCT values.

It's relatively easy to calibrate white point of inexpansive, normal gamut display, while it's more challanging for a simple colorimeter to calibrate white point on wide gamut CCFL, W-LED and RGB LED backlit display.
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Marcin Kałuża | [URL=http://zarzadzaniebarwa

olje

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #4 on: April 08, 2012, 01:34:10 pm »

Aha, Ok,

just so that I understand, which one of my original calibrations are closer to match the calibration target.

Are you suggesting that my original colornavigator calibration is the exact one and that I should match my SpyderElite calibration on the FS2402 to the colornavigator calibration on the CG243? or vice versa?

If the first suggestion, then I agree with you of course that the D50 calibration is too warm to match the printout from the printer. Then I should more likely use a calibration target of 5350K to match the printout.

Thanks in advance,

Best Regards,
Ola
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Czornyj

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #5 on: April 08, 2012, 01:55:12 pm »

It's possible that both calibration don't really match the calibration target:
http://www.luminous-landscape.com/forum/index.php?topic=53825.0

But even if one of them matches the target, it doesn't necessarly mean you should get a visual match with the print. It's most likely that the spectra of light illuminating the print is not exactly D50 - and even if it was, the spectral reflectance of paper may change it.

To put it in simple words - in a real world there's no universal target that will give you a visual match with the print:
http://www.luminous-landscape.com/tutorials/why_are_my_prints_too_dark.shtml
« Last Edit: April 08, 2012, 01:57:05 pm by Czornyj »
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Marcin Kałuża | [URL=http://zarzadzaniebarwa

olje

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Re: Issue with white point temperature Eizo CG243 and ColorNavigator?
« Reply #6 on: April 08, 2012, 04:29:32 pm »

Thanks
Ola
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