QTR-Quadtone RIP

In a recent thread I had, Paul Roarke Suggested I use the BOOST_K= field, as I was having difficulty profiling UT14 to Epson Premium Glossy Photo Paper.  On the profile I have, Dmax is about 1.93.  I have got the Dmax up to 2.60, although this was when heavily saturating the paper, I would have thought I could possibly get up to about 2.20 without over -saturation.

I can't see any instructions on the literature I've found about this feature.  Could anyone point me to something or explain the use of this, in terms aimed at a TechnoKlutz.

I would also be interested in the use of the GRAY_HIGHLIGHT=, GRAY_SHADOW=,  The literature I have is a bit brief, stating that lowering from 10. lightens either the shadows or highlights.  Can you go above 10?  Is this a sort of try it and see feature?  Also the literature conflicts with one setting 10 as a default and the other 6, or some other.

I'm not sure of the GRAY_OVERLAP= feature either.

Ross

Ross,
    I haven't used these features much, but here is what I know (or think that I know):

I believe that the Boost_k parameter will only affect the K ink (eboni black in UT-14), which I presume that you are not using with the glossy papers.

The gray_highlight and gray_shadow parameters change the shape of the ink curves, but not the maximum ink densities.  These can be useful in adjusting the curves before linearization, but I don't think that they will affect Dmax.

I don't think that I have gotten Dmax significantly over two on any glossy paper.  My own view is that many people worry too much about Dmax.  Keep in mind that D=2 means that only 1% of the light hitting the paper is reflected.  A D=2.2 is 0.06%.  Visually, the difference is barely perceptible.

David

--- In QuadtoneRIP@yahoogroups.com, "rossfmj"  wrote:

>
> In a recent thread I had, Paul Roarke Suggested I use the BOOST_K= field, as I was having difficulty profiling UT14 to Epson Premium Glossy Photo Paper.  On the profile I have, Dmax is about 1.93.  I have got the Dmax up to 2.60, although this was when heavily saturating the paper, I would have thought I could possibly get up to about 2.20 without over -saturation.
> 
> I can't see any instructions on the literature I've found about this feature.  Could anyone point me to something or explain the use of this, in terms aimed at a TechnoKlutz.
> 
> I would also be interested in the use of the GRAY_HIGHLIGHT=, GRAY_SHADOW=,  The literature I have is a bit brief, stating that lowering from 10. lightens either the shadows or highlights.  Can you go above 10?  Is this a sort of try it and see feature?  Also the literature conflicts with one setting 10 as a default and the other 6, or some other.
> 
> I'm not sure of the GRAY_OVERLAP= feature either.
> 
> Ross
>

David

Thanks again.

The reason I was asking is that I've printed a few of my own images on the UT14 cool profile I've made.  The images seem to lack some "punch".  It may be more an issue of the colour/printer profile, viewing conditions or screen brightness, which I also need to work at understanding.

Additionally I may be able to reprofile with a default ink limit slightly higher, I could have guesstimated a bit low from the plotted density levels (30%).  The plot of the density levels I measured did not have quite the same sort of sharp transition as the one you posted.  I may go for 35% to see if it makes any noticable difference.

I asked about the SHADOW and HIGHLIGHT values, as when I viewed the test "bulls eyes" on my previous profile, there appeared to be a noticable step between the lighter values and darker ones.

Ross

--- In QuadtoneRIP@yahoogroups.com, "David"  wrote:

>
> Ross,
>     I haven't used these features much, but here is what I know (or think that I know):
> 
> I believe that the Boost_k parameter will only affect the K ink (eboni black in UT-14), which I presume that you are not using with the glossy papers.
> 
> The gray_highlight and gray_shadow parameters change the shape of the ink curves, but not the maximum ink densities.  These can be useful in adjusting the curves before linearization, but I don't think that they will affect Dmax.
> 
> I don't think that I have gotten Dmax significantly over two on any glossy paper.  My own view is that many people worry too much about Dmax.  Keep in mind that D=2 means that only 1% of the light hitting the paper is reflected.  A D=2.2 is 0.06%.  Visually, the difference is barely perceptible.
> 
> David
>