[argyllcms] Re: Awful result with Argyll 1.3.5 + dispcalGUI 0.8 + i1Display Pro & Dell U2711 :-(((

  • From: Paolo Avezzano <info@xxxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 13 Jan 2012 00:42:17 +0100

On 13/gen/2012, at 00:28, Graeme Gill wrote:

> Paolo Avezzano wrote:
>>   do you have any link with a test on this?
> 
> There was some discussion a while ago on this list. Adjusting the secondaries
> (CMY) to be an additive combination of the primaries (RGB) proved to
> be fiddly, and not very sucessful (matrix profiles fitted poorly).
> There were hints that the RGBCMY transform the display was applying
> was clipping the gamut.

OK, I'll try standard as well and test for gamut volume.


> 
>> I just made a XYZLUT+MTX profile and everything is quite good, except for:
>> - global greenish hue
> 
> Compared to what ?
> 
> A purely subjective impression isn't much value I'm afraid,
> since our visual system is so quick to adapt to various
> influences outside the display itself.
> 
> If the white point hue doesn't match 50% gray, then that's a problem
> that bears investigating.
> 
> If the whole response is far from daylight/black body, then this
> indicates a problem with the instrument absolute accuracy.

Compared to the i1Profiler and, for what is worth, for my taste.
I used the same 7200K for both test. I'm not saying is way off, just a bit 
greenier.


> 
>> - far from neutral darkest grey patches
> 
> Note that the default for LCD is not to adjust the black end for
> neutrality, so as to preserve the best possible contrast range.
> You can fiddle with the crossover rate between the corrected
> neutral and black using "dispcal -A rate". Try something like 8.0
> to push the correction closer to black.
> You can also have correction go all the way to black by using
> "dispcal -k 0.0" (or some in-between value), but your contrast
> ratio will suffer. In theory you could also change your white point
> to better match your black point, but the visual result may not
> be desirable.

I suspect I can't set these advanced parameters under dispcalGUI: I'll have to 
test Argyll under command line again tomorrow.
Thanks for the info, appreciated.

Paolo

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