QTR-Quadtone RIP

I can't help with Mac-related issues (I'm PC), but be sure the 21-step test
print you use for linearization was printed after the previous
linearization values were removed.

The plot in Excel of the Lab L values should be a straight line.

Paul
www.PaulRoark.com

On Sat, Feb 2, 2013 at 3:03 PM, rossfmj <ross.jarvis@...> wrote:

> **
>
>
> I have been trying to create my first profile for QTR to match budget
> Cartridge World matt photo paper to the UT14 ink set.
>
> I used Dave Goldenberg's Matt cool profile ink descriptor (EEM) as a base
> to work from.
>
> I was assuming that I'd get a relatively straight line of plotted
> luminosity values at the end of the process. However, comparing the plots
> (line chart in Exel) of the Luminosity value of Dave's original profile to
> my new one, it appears that the original is straighter than my profile.
>
> Looking at Keith Cooper's test prints made with both these profiles, I can
> see that Dave's profile gives much smoother transitions than mine, as seen
> in the round thingumajig at the top. I can see more detail in the shadows
> created by my profile, but this may be a function of having a lower maximum
> density.
>
> I'm thinking I'm not getting something right here so would appreciate any
> advice. I have placed copies of the plots in "Photos" in this group
>
> The procedure I used to make the profile was;
>
> Find printer ink limit using inkseparation6.tiff, reading values with
> Spyder3print.
> Reprint inkseparation.tiff to get crossover values.
> Using Dave's Ink Description Files as a template, I put printer details
> in, reset the values for default ink limit and the other two channels used
> (these were different to Dave's through my earlier checks). I didn't get
> what the values for Gray Highlight and Gray Shadow were for, so left these
> at 10 each. Next I used Installcommand to load the profiles into
> HD/Library/Printers/1400.
> Using this profile with Dave's linearise values I printed a 21 step wedge
> and then read and noted the Density values. I then put these new values in
> to replace Dave's linearise values in the original text file for this
> process, which is in Documents.
> Next I dropped this file into Drop-Quad-Profile. (At this point I'm a bit
> hazy as I've been sat at the laptop since Thursday, learning the whole
> process from scratch).
> I then installed the new profile and printed a new 21 step wedge. This is
> the one I've used to produce my own chart in photo's.
>
> 1, any obvious errors in my approach?
> 2, am I correct assuming the luminosity values plot should be
> straight(ish)?
> 3, should I be aiming for a straighter plot?
> 4, Gray Highlight and Gray Shadow values in the profile are given with
> different suggested numbers in the different tutorials I've read. What are
> these for? and how do you determine what to set them at?
> 5, the test print indicates poor transitions, would the non-linearity of
> Density values cause this, or may this to be due to Gray Highlight Gray
> Shadow values.
>
> Apple OSX 10.8.2
> PS Elements 11
> QTR 2.7.2
>
> thanks for any help
>
> Ross
>
>  
>


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