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QTR Curve Creator and Channel Density - what is the exact function?

2014-10-21 by amog19@...

Hi Everybody,


I am following Roy's advice and manipulate the R3000 K3 channels to develop my understanding of QTR. Consequently questions come up - e.g. this one:


What function does the "Density" variable in each color channel exactly have? Does it define the threshold N, up to which densities <= N are assigned to the corresponding ink channel, while densities > N are assigned to the channel with the next higher Density?


Background for my question: when I review the QTR tutorials from different authors on Curve Creator / Creation and how to evaluate the inkseparation print, they always match the 100%-patch of e.g. LK with a patch in K that has equal / similar density und use Its value as the Density value for LK.

But: When I look at the color strips on the inkseparation print, I see that for each color / strip there is an "operational range" within which the printer renders a color optimally: below 15%-20% dithering becomes visible, so I want to cut it off. At / over e.g. 40%-90% (depending on the overall density of the given color channel) the color maxes out, so I want to cut that area off too. So the operational range that I would want to allow for a given color channel may be 15% - 50%. All densities >50% I would want to assign to the next higher channel.


Does at this point "Density" have the impact that it limits the densities that are assigned to the affected channel to <= N? Example: let's say an 100%-LK has a density equal 30% of 100%-K. According to above mentioned tutorials I would have to enter: LK Density = 30. Accordint to my own reasoning regarding the operational range I would enter: LK Density = 15 (because my LK maxes at 50%).


This leads me to halt in confusion and ask the question: what exactly is the function of "Density"?


Looking forward to your reponses,
Amin

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