How to verify if DisplayCal is doing anything

[anthonyefarr]

Hi

I’ve reset the Windows 10 installation on my laptop. Thus I’ve also had to reinstall DisplayCal.  Previously DisplayCal had a marked effect on the built in display but now I can’t see any effect.  Before I start into fault finding I’d like to be certain there is a problem. So my question is:

Is there any way of telling whether DisplayCal is doing anything – eg by flicking it on & off?

Thanks

Tony

[Vincent]

There should be a DisplayCAL tray app (next to date, lower right). If there is no tray app, reinstall your older profile using DisplayCAL (jus reinstall it, no need to make a new one).

[anthonyefarr]

Hi Vincent,

The tray app is there. But I’m still not convinced that it’s making any difference to the colours of the display.

Tony

[Vincent]

Then check if the profile you made is selected as default profile for that display in DisplayCAL tray app.

If it is not, select it.

Then use tray app to reset video LUT contents to linear values (ouput is the same as input). That cleans GPU calibration. Unless your uncalibrated display amost matches your calibration target, this is going to be visually noticeable.

If you use Displaycal profile info (“i” button in DisplayCAL) you can see calibration curves stores in profile to get a visual inspection: if they are almost a 45 degree line or not.

[anthonyefarr]

Hi Vincent

Thanks for your reply.

You say “reset video LUT contents to linear values”. I cannot see that option. Do you mean “Reset Video Card Gamma Table”? I’m using v3.8

The “i” button shows curves that aren’t straight lines so that’s promising.

Regards

Anthony

[Vincent]

Hi Vincent

Thanks for your reply.

You say “reset video LUT contents to linear values”. I cannot see that option. Do you mean “Reset Video Card Gamma Table”? I’m using v3.8

Yes, I did not remember the exact literal sentence, just wrote what that option actually does.

The “i” button shows curves that aren’t straight lines so that’s promising.

Regards

Anthony

“Reset” set to linear (a.k.a. “clean”)

“Load calibration form current profile” loads into GPU LUT the contents of VCGT tag (3 x 1D LUT tables) stored in your “default” display ICC/ICM profile, as configured in your OS’ color management configuration (Control Panel \ color management in Windows but Windows10 may have another shortcut to that in its new/aternative user interface)

So using that 2 options in tray should change your display response with a profile like the one you report.
If it does not work, “no change”, you may need to run command line the equivalent ArgyllCMS command used by DisplayCAL with high verbose in order to see if ther is some error when ArgyllCMS try to access video card’s LUT. Florian or Graeme could guide you better in that diagnosis stage… but I hope that tray app works without issue for you.

[anthonyefarr]

Hi Vincent,

Fixed! I’ve confirmed that DisplayCal is working & I believe the reason it didn’t look right was because I’d selected the wrong instrument mode (CCFL vs WLED).

You said:

“Load calibration form current profile” loads into GPU LUT the contents of VCGT tag (3 x 1D LUT tables) stored in your “default” display ICC/ICM profile, as configured in your OS’ color management configuration (Control Panel \ color management in Windows but Windows10 may have another shortcut to that in its new/aternative user interface)

I was with you up to “Load”.  😉

Thanks

[Author]

Posts