Digital BW, The Print

i posted this question on the QRT forum, but have received no 
response.
i was hoping someone here may be able to help.


Is this possible?

when working in the "curve creation" mode, if you select "load
curve" as opposed to "gray ink" or "toner" you get a curve tab where
you would normally enter the ink density.
from that point, you can open up the "curve points/point list". it
appears the only way to get information there is to enter it manually.
is it possible to load or display the information (points) from a
curve that has been created with the "toner/density/limit" method.

in other words, if I where to open up a UCpk-raw-neut curve (on a
3800), could I display the curve in the point list that was created
for the light magenta channel when it was selected as a toner 2 with
a density @ 25 and limit @ 6 originally?

I hope to take that toner curve, and make very small adjustments to
it, but I want to use the current curve as my starting point as
opposed to creating one totally from scratch.

any help would be greatly appreciated.
Evan

When you open the curve in the Curve Creator you can hit "Show Curve" 
and see the graph of the various ink curves.  From this you can 
simply transfer the graph plots to the point list.  You can use a 
screen grabber to capture the curve and print it. 

The curves in the final "Show Curve" graph are shown after the ink 
limits are applied.  You can change those ink limits to 100 to expand 
the curve and get a better idea of the points.  You can still apply 
the previous ink limits to the Point List curve when done.

I tend to always use the Points List so that I and others can see 
what is going on and easily transfer the curve to another profile or 
ink, or make small changes.  Although the linearization step is 
wonderful, I still think a fairly smooth curve going into that step 
results in a better profile.

Hope this helps.

Paul
www.PaulRoark.com 


- In DigitalBlackandWhiteThePrint@yahoogroups.com, "evanj1969" 
<evanj69@...> wrote:
>
> i posted this question on the QRT forum, but have received no 
> response.
> i was hoping someone here may be able to help.
> 
> 
> Is this possible?
> 
> when working in the "curve creation" mode, if you select "load
> curve" as opposed to "gray ink" or "toner" you get a curve tab where
> you would normally enter the ink density.
> from that point, you can open up the "curve points/point list". it
> appears the only way to get information there is to enter it 
manually.

> is it possible to load or display the information (points) from a
> curve that has been created with the "toner/density/limit" method.
> 
> in other words, if I where to open up a UCpk-raw-neut curve (on a
> 3800), could I display the curve in the point list that was created
> for the light magenta channel when it was selected as a toner 2 with
> a density @ 25 and limit @ 6 originally?
> 
> I hope to take that toner curve, and make very small adjustments to
> it, but I want to use the current curve as my starting point as
> opposed to creating one totally from scratch.
> 
> any help would be greatly appreciated.
> Evan
>

thanks paul,
what you described is exactly what i've been trying tonight. i had 
just hoped there was going to be an easier way. once i get the first 
curve done, i'm sure it'll all be easy to copy/paste or modify to 
other papers from there.

one question though. i understand when you say change the ink limits 
to 100 to expand the curve (to see it better), but should i leave the 
density where it is? it seems that if i change the density to 100, 
the 
entire shape of the curve is changed to something it was NOT.

i'm starting to understand when you said .... like IJC curves, but 
with more control.


thanks as always
evan


<pr_roark@...> wrote:
>
> When you open the curve in the Curve Creator you can hit "Show 
Curve" 
> and see the graph of the various ink curves.  From this you can 
> simply transfer the graph plots to the point list.  You can use a 
> screen grabber to capture the curve and print it. 
> 
> The curves in the final "Show Curve" graph are shown after the ink 
> limits are applied.  You can change those ink limits to 100 to 
expand 
> the curve and get a better idea of the points.  You can still apply 
> the previous ink limits to the Point List curve when done.

Evan,

>... i understand when you say change the ink limits 
> to 100 to expand the curve (to see it better), but 
> should i leave the density where it is?

The density is, I think, just used for the partitioning.  When you 
manually write a curve it is not used.


> i'm starting to understand when you said .... like IJC curves, but 
> with more control.

Yes, lots of points and very fine control potential.

Paul
www.PaulRoark.com

sorry, i should have been looking at the program when i asked that 
question. i see that the density is not an option at that point.


OK, so when i create a curve in the "point list" and look at the 
preview via "preview curve", it looks like the one i am trying to 
copy. when i click OK, then click "show curve". the one i am 
presented with looks much different (in terms of it's shape). i have 
been working at it for hours, but seem to be spinning me wheels.

which of the two would i expect to be more accurate?
should i try to use less points or more? i have placed one every 10 
points (10,20,30,40, etc)


evan

> >... i understand when you say change the ink limits 
> > to 100 to expand the curve (to see it better), but 
> > should i leave the density where it is?
> 
> The density is, I think, just used for the partitioning.  When you 
> manually write a curve it is not used.

Evan,

>... so when i create a curve in the "point list" and look at the 
> preview via "preview curve", it looks like the one i am trying to 
> copy. when i click OK, then click "show curve". the one i am 
> presented with looks much different (in terms of it's shape). 

The preview curve does not show the effects of the smoothing algorithm, 
and perhaps other factors.  So, you'll notice bulges, etc. in the final 
one if you have sharp turns and the like.  The curves can also "bounce" 
off the base occassionally.  Once you get the hang of it, you'll find 
it's rather easy to put more points in turns to smooth them.  Sometimes 
several points spaced at just one integer apart overcome the problems.

Paul
www.PaulRoark.com

I figured it out.
 the linearization data that was entered was throwing my curves WAY 
out of wack. (I was using a MSR-neutral curve as my starting point)
 once I cleared all the figures out, my preview in the and "point 
list", and my curves via "show curve" look almost identical.


 it's all coming together after several days of experimenting.

 so in your experience, if using the "point list" option, it "seems" 
that the "black boost" no longer works, but I assume that 
the "default ink limit" does.
 is that correct??


 thanks as always paul, and to all those that offer so much help here

 evan


> The preview curve does not show the effects of the smoothing 
algorithm, 
> and perhaps other factors.  So, you'll notice bulges, etc. in the 
final 
> one if you have sharp turns and the like.  The curves can 
also "bounce" 
> off the base occassionally.  Once you get the hang of it, you'll 
find 
> it's rather easy to put more points in turns to smooth them.  
Sometimes 
> several points spaced at just one integer apart overcome the 
problems.

> 
> Paul
> www.PaulRoark.com
>

Evan,

> ...
>  so in your experience, if using the "point list" 
> option, it "seems" that the "black boost" no longer 
> works, but I assume that the "default ink limit" does.

I assume the black boost will still override the Black ink limit.

As a practical matter, I have not been using it becuase I tend to set 
the limits at where I find the dmax is reached.  One could set it a 
bit lower and then put the black boost at the max point.  This might 
give more flexibility to raise or lower is as circumstances changed.

Also, my understanding of the black boost is that it's not just a 
higher limit.  It puts a very steep curve on the black ink at the 
very end.  This is to overcome the usual rather flat response of the 
paper and ink as the limit is approached.  It might be easier to put 
that steep curve on with the black boost than with a manual curve.  
On the other hand, I tend to also do that manually, with, for 
example, a point at 98 that is quite a bit below the final point.

At any rate, I think the option of using the black boost is there 
even if the points list curve generation is used.

Paul
www.PaulRoark.com

Evan,

> ...
>  so in your experience, if using the "point list" 
> option, it "seems" that the "black boost" no longer 
> works, but I assume that the "default ink limit" does.

I assume the black boost will still override the Black ink limit.

As a practical matter, I have not been using it becuase I tend to set 
the limits at where I find the dmax is reached.  One could set it a 
bit lower and then put the black boost at the max point.  This might 
give more flexibility to raise or lower is as circumstances changed.

Also, my understanding of the black boost is that it's not just a 
higher limit.  It puts a very steep curve on the black ink at the 
very end.  This is to overcome the usual rather flat response of the 
paper and ink as the limit is approached.  It might be easier to put 
that steep curve on with the black boost than with a manual curve.  
On the other hand, I tend to also do that manually, with, for 
example, a point at 98 that is quite a bit below the final point.

At any rate, I think the option of using the black boost is there 
even if the points list curve generation is used.

Paul
www.PaulRoark.com