QTR-Quadtone RIP

In case others are interested, I took Howard's advice and I wound back
the ink limit to 55% (where there is a clear step to either side). 
Re-partioned the gray ink and adjusted its limit.  Resultant wedge was
good.  It linearised fine and the resulting dMax is 1.59. More
important to me is a nice smooth gradiant.

Now for the cool curve.......

Cheers, --Kip

--- In QuadtoneRIP@yahoogroups.com, "Kip Cole" <kipcole9@...> wrote:
>
> Howard, thanks for the advice.  The ink limit in the HPR curve I've
> been working from is 75%.   When I measure around that point on a the
> ink limit calibration chart at 100% I get:
> 
> Step     L*
> 50       17.5
> 55       17.8
> 60       18.2
> 65       18.4
> 70       18.6
> 75       18.8     ==> Chosen as ink limit
> 80       18.8
> 85       19.0
> 90       18.8
> 95       19.4
> 100      19.5
> 
> As you suggest, the 75% step is very close to the 80->100 steps, and
> the 70% step too.
> 
> Based on this data, what ink limit would you try as a base.
> 
> Cheers, --Kip
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@> wrote:
> >
> > Kip Cole wrote:
> > > I have finally been able to dedicate my old 2100 to QTR and am
> > > starting with standard UC until I get comfortable with curve
creation
> > > in a "2k" system.
> > > 
> > > I am trying to create a warm curve for HPR.  I have tried as a base
> > > curve the EEM curve in the QTR distribution and also Mr. Schofields
> > > HPR curve at
> > >
>
http://homepage.mac.com/WebObjects/FileSharing.woa/wa/default?user=scho&templatefn=FileSharing2.html&xmlfn=TKDocument.2.xml&sitefn=RootSite.xml&aff=consumer&cty=US&lang=en
> > > I am creating step wedges of non-linearised curves in all cases.
> > > 
> > > For all my tests I'm getting density reversal in the 100% step
(using
> > > the 21step.tif file).  I'm getting around 19.1 to 20.2 L* in
this step
> > > depending on my adjustments, and a good ramp from around 18.5 L* on
> > > the other steps.  All measured with EyeOne/MeasureTool.
> > > 
> > > Have tried adjusting black boost, gray overlap (even up to 100%),
> > > shadow adjustment but to no avail - the 100 step is always lower
> > > density. The curve uses only Mk and Lk as you would expect.
> > > 
> > > I know this is a little trial and error involved but after about 20
> > > experimental step wedges I figure some advice and guidance would
sure
> > > be appreciated,
> > > 
> > 
> > Kip
> > 
> > I would suspect the ink limit on K. What are the readings for K on
the 
> > calibration strip for the limit you have used and the two steps
either 
> > side? Sometimes it's worth pulling the limit a little back from the 
> > maximum dmax step to make sure you have good separation between the
> step 
> > at the limit and the step before it. The maximum can then be 
> > re-introduced via black boost.
> > 
> > You could also try an overlap of 0 if you haven't tried that yet.
> > 
> > Howard
> >
>