[argyllcms] Re: Problems with dispcal and DTP94

  • From: Florian Höch <lists+argyllcms@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Thu, 05 Feb 2009 17:11:15 +0100

Roger wrote:
I'm using Florian Höch's excellent dispcalGUI 0.2.1b (please add the version
number in the About screen Florian?).

Thanks :) And I'll add the version in the next update (which should be ready soon, but with no new features - just some bugfixes and small changes).

a) Reset LUT curves

Resetting the LUT manually is not absolutely needed, because dispcal will also reset it when run. Still, it will do no harm either.

b) In the Settings menu, make sure that the selection is "empty"
   (perhaps, in the future, this should be made more explicit, with a menu
entry like
   (new calibration, otherwise, it is confusing where the calibration goes)

Duly noted.

c) Under Profile name, type is something meaningful like "DTP94 Cal=Low"
   (that way, at the end of calibration, it is possible to follow what's
going on (in the CMD window, because dispcal echoes the .cal filename)

I'm currently rethinking the default naming scheme of dispcaLGUI, to make it a bit less cryptic. Maybe something like <display name>-<color temp>-<brightness>-<gamma>-<date>, eg. mydisplay-6500-120-2.2-20090205 I will also implement a way for users to select their own preference from pre-defined variables.

d) Press Calibrate only button
e) Press the Load Settings icon and select the .cal file to make it active
f) Type in some meaningful profile name or accept default
   I use Profile quality = Low with Profile type = LUT
g) Press Profile only button (I use 127 testchart)

In that case you could also use "calibrate & profile". This runs the same utilities in the same order (dispcal - dispread - profile) but saves you one click (and I think, after "calibrate only" the right .cal file should already be selected automatically, but I'll have to recheck what I did there).

To profile with the DTP94 also takes 8 minutes. I was surprised that I was
not ask to put the instrument on some black surface to calibrate.

Interesting. I did not add a checkbox for the instrument calibration part because I only have a i1display2 and i1pro to check, and both run their internal calibration without specifying it explicitly. Maybe I should add an option for this. Do your calibration results with the DTP94 improve if you run dispcal -K through the commandline with the same options as in dispcalGUI? (if yes, I should maybe set the -K option automatically if a DTP94 is detected)

On another note, I should maybe also add the -N option for dispread (disable auto instrument cal) if dispcal and dispread are run in succession, upon re-reading the Argyll docs I think it is not necessary to do it again in dispread if dispcal did it before.

I calibrated Native and must have around 115 cd/m2. I use a gamma of 2.2.
Black offset = 0%.

Just as a side note, in the next version of dispcalGUI I will default the gamma to 2.4 so that it uses Argyll defaults (which work pretty well for many cases - the initial 2.2 in dispcalGUI was actually a mistake on my part, as I originally intended to use Argyll defaults everywhere, but my memory failed me ^^).



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