QTR-Quadtone RIP

Michael, Lou,
I just installed the update to Spyder3print and only spent one evening
trying to get the right tone for my R1800. I have seen that the
QTR-program refuses to linearise when either some values increase
instead of decrease or, as Lou points out, the values of 80-85-90-95
and 100% are to close so that the curve flattens. A good help is
entering the data from QTR (or directly from your readings) in a
spreadsheet and then let it draw a graph. You will immediately see if
there are values out of order or if the tail of the curve platforms.
This is a problem I have wher my values for 80 .. 100% are 30.25 28.72
27.5 27.43 27.36. You see that there is little difference and I think
I might have to limit the amount of ink to below 70%.
Lou, to assure you the program doesn't bomb.
Regards to all,
Jean



--- In QuadtoneRIP@yahoogroups.com, "Louis Dina" <lou@...> wrote:
>
> Michael,
> 
> I always use the 21 step random target for linearizing in QTR and it 
> works just fine.  The only time I have had problems was when shadow 
> values were so close and bunched up that QTR decided they were too 
> close.  If there are reversals, then it definitely bombs.  The 
> solution in that case is to change the parameters and get more 
> separation between shadow steps before trying to linearize.  That can 
> be done in a number of ways.  
> 
> I felt that the 51 step wedge had too many steps for linearization 
> and would probably make it even harder to get data that didn't have 
> crossovers.  So, I always used the 21 step random file.  I use an 
> EyeOne, but that shouldn't make any difference.  
> 
> If you get that error message when trying to linearize using the 
> droplets, the I suspect your values are too close together at some 
> point in the tonal scale.  
> 
> Hope this helps.
> 
> Lou
> 
> --- In QuadtoneRIP@yahoogroups.com, "michaelrosensf" <Michael@> 
> wrote:
> >
> > I'm the originator of this thread, which has generated discussion 
> about Spyder3Print. 
> > However, my question has never been addressed.
> > 
> > I'll rephrase. Has anyone successfully used one of the random step 
> wedges to linearize or 
> > make an ICC profile by dropping the file obtained from reading the 
> patches on QTR-
> > Linearize-Data or QTR-Create-ICC? On a Mac?
> > 
> > I'm unable to get even the supplied sample files (e.g., QTR-51-
> random) to work. I get the 
> > message "Lab values not in order. Cannot Linearize" (or "Cannot 
> Create ICC").
> > 
> > Help!
> > 
> > Michael
> >
>