[argyllcms] Re: Calibration issue with colormunki

  • From: Emmanuel Michonneau <emmanuel.michonneau@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 21 Nov 2010 18:37:06 +0100

Hello Juergen,

Thanks for your answer.

About, the matching white point, as I said the monitor was in "factory
setting" during my test.
When I set a white point near 6500K curves look like that:
http://emmanuel.michonneau.free.fr/pub/Curves_colormunki_6500.png
http://emmanuel.michonneau.free.fr/pub/Curves_spyder_6500.png

=> This accentuate the difference between colormunki and spyder2. Why
response curves of colormunki does not start to zero?

I think the reality is somewhere between the two instrument mesurements.
Spyder2 profil tends to over dark image and loose details in the shadow.
But colormunki profil makes the shadows unreal...

To illustrate my problem here are 3 screenshot of the same photo with
respectively :
- no profil : http://emmanuel.michonneau.free.fr/pub/withoutprofil.jpg
- Spyder profil : http://emmanuel.michonneau.free.fr/pub/spyder_argyll.jpg
- Munki profil :
http://emmanuel.michonneau.free.fr/pub/colormunki_argyll.jpg

Note the difference particulary on the steps downside of the picture.
Since the steps are backlight illuminated by the street light they normaly
have to be very dark.
On the color munki profiled image, they seems to be over exposed and strange
artefacts appears.

Of course this picture has not been postprocessed. It is just a raw
converted to jpg.

Does the problem comes from my display and its TN panel?
Normaly it show be good enough to be calibrated with precision as said in
the reviews :
http://www.prad.de/en/monitore/review/2007/review-hp-w2408h-part9.html#Measurements

Best regards,
Emmanuel

2010/11/21 Juergen Lilien <jp.lilien@xxxxxxxxxxxxxx>

> Hello Emmanuel,
>
> > I have tried to use adaptive and hires modes of the colormunki. This
> > improves a little the results in calibration but the generated profiles
> are
> > still too brigth in darks tones.
>
> my experience is, that I get better results with adaptive and hires
> enabled, especially the hires mode seems to have influence on the
> brightness measurement.
> There is no general problem with the Colormunki and to bright dark
> tones. If I had to decide, I would say, my dark tones are (if anything)
> a little to dark. ;-)
>
> > Do I miss something in the use of colormunki?
>
> You should definitely try to set a better matching whitepoint with the
> monitor controls in the dispcalGUi calibration stage.
>
> And there is always the possibility to try the original Colormunki
> software, to have a third result to compare.
>
> Regards, Juergen
>
>

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