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
Message
Re: [QuadtoneRIP] QTR Curve Creator and Channel Density - what is the exact function?
2014-10-21 by Paul Roark
I wrote a simplified approach to QTR profiling starting at page 11 of http://www.paulroark.com/BW-Info/Eboni-4-Plus.pdf . The inkset doesn't matter that much with respect to the basic way in which the program partitions a multi-ink channel -- like the Gray one.
Density gives the program part of what it needs to determine the order and range of the inks for partitioning.
Profiling is a bit of an art. You'll learn as you go.
Good luck.
Paul
On Tue, Oct 21, 2014 at 2:46 PM, amog19@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote: