QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "Jeff Kohn" <jkohn@...> wrote:
> Are you using the 51-step chart? I sometimes got the same result 
when trying
> to linearize using the 51-step test chart. It seems that even 
though the
> steps were increasing, the difference between some steps was so 
small that
> QTR didn't seem to like it. 


Hi Jeff,

No, I use the 21-step wedge. But triggered by your reply I have 
studied the L values I measured (with Measure Tool. It is working 
fine now). This is what I got:

LINEARIZE="96.11 89.48 82.23 74.89 68.38 61.88 55.86 50.32 45.93 
42.21 38.85 36.25 33.71 31.38 28.64 25.46 23.52 21.37 19.5 18.69 
15.31"

Note the last three numbers. The 90% and 95% values are fairly close 
and then there is a sudden drop for the 100% (black). If I 
artificially change the 18.69 in 17.69, the error message disappears. 

My conclusion is that my curve parameters are way off from the 
optimum. I guess I have to fiddle with the ink limit and black boost 
parameters. So the error is on my side.

As a suggestion to Roy: it would be nice if QTR could give clearer 
error message in a case like this.

Joost