[argyllcms] Re: Display Calibration. Setting up RGBCMY Hue/Saturation controls.

  • From: Ivan Kadomin <ivan.kadomin@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 18 Mar 2011 14:11:38 +0300

From what you wrote, I think you have a display with the exact same behavior than my U2410 A02 (Is it the same or the new ASUS IPS model?)
János, you are the telepathist. Exactly! My display is Dell U2410 (Rev. A02). :)

If you resist, I think you can use CalPC (a software from spectracal who sells CalMAN for TVs) to set up the 6-axial color controls. (There is a demo without actual sensor support to see what options it offers.)
Ok, may be I will play with it. It seems it supports ColorMunki which I'm using.

But I suggest your to spare the long hours fighting with your display. The Custom mode will NEVER be accurate.
In "Custom" mode with default OSD settings (RGBCMY Hue/Saturation = 50) I achieved dE2000 about 1.4 max and 0.2 avg. And my impression of gamut were like ... Hmm, "Standard" looks more saturated in comparison to "Custom". After some empirical adjustments of RGBCMY Saturation (GCY=100, RM=48, B=58) I achieved dE2000 about 4.5 max and 0.6 avg. And now my impression of the gamut is ... Wow, "Custom" can be so reach in colors and "Standard" looks dim in comparison to "Custom". Though after raising up saturation I noted some artifacts, e.g. thin gray lines about 1-1.5px witdth or gray text on a black or on a dark gray background can be grin/pink colored at one side. But I'm Ok with it, since cases when I should look down to pixels are rare in my workflow.

Your only choices are:
1: use the factory calibrated Adobe and sRGB presets for the corresponding materials (you can probably change their white point in the service menu and try to calibrate them via the VGA LUT, but it won't be very accurate),
2: calibrate and profile the Standard mode. To do this right:
- Optionally enter to the factory/service menu and tune the RGB Gains there (the preset which corresponds to the Standard mode, like 6500K) to either maximize the contrast ratio (RGB=255) or set your desired white point as close as possible (but keep the highest value at 255). - Remember to select the Standard mode again after you exit from the Factory menu. - Run a Medium or High quality calibration with native targets: native WP, native black/white luminance, 100% black output offset, 0% black point compensation (Optionally try to find the lowest rate, I kept the 4.0) - Construct a very basic profile ("single gamma + matrix") from a few patches. - Use this mode with high quality CMS softwares. (Use the Relative colorimetric intent if you tuned your WP or the Absolute intent if you didn't.)

* Because the Absolute intent doesn't really seems to work in some softwares (like PhotoShop in many cases) and the device may shows broken near-black and/or near-white output with RGB=255 setting, I think it's safer to set the WP to the desired value in the service menu instead. (You will end uo with slightly lower contrast ratio but sightly more accurate result too...)

** If you don't want / unable to acces the srvice menu, you can skip this step. But you have to set the your desired WP as a calibration target or use the Absolute colorimetric rendering intent in softwares.
Thanks for the advices, I will use some of them.

Best regards,

Other related posts: