QTR-Quadtone RIP

Hi Paul,

--- In QuadtoneRIP@yahoogroups.com, "pr_roark" <paul.roark@...> wrote:
>
> Hi Steve,
> 

> You could also just print the necessary 21-step test strips to do a fresh partitioning.  You might end up with a closer fit to the ink.  But you may not want to get into this yet....
 
> That is one of the reasons to start from scratch.  The curve you're starting with is probably not very well partitioned for the ink you're using....

Do I start from a completely zeroed out *.qidf file without any information entered into the fields?

> I actually prefer compressed shadow tones on pre-linearization curves, as long as there is some minimum separation so that QTR doesn't refuse to partition the input. 

The minimum separation is a problem, but I only have an Epson Scanner to scan the image then convert to Lab mode and measure the steps with the "Info" window.

> Many of the errors I see in final curves are due to the software not having enough deep shadow information.  If the information is not there QTR will interpolate. In the deep shadows where the curves are in steep cross-overs the interpolation may miss the mark.

The separation in the deep shadows are separated by steps of just one or two for about the first 5 or 6 steps from the deepest black.

So far as the linearized curve, it looks like a shallow bowl tipped up on its side. The straight line curve or at least close to a straight line, doesn't exist.
 
> I prefer to read the 21-step curves with a spectro and then graph the results. 

As I said above I only an Epson scanner and not a spectro.

Steve Law