QTR-Quadtone RIP

Hello list,

I would like to learn how to make QTR curves. I made
two tests with 100% and 85% ink limit. Now I want to
do the ink density calibration. Here is the
explanation in the QuadTone RIP User Guide:

*****************************************************
With a densitometer: 

1. measure the 100% Light Black patch: Density 1.29
 
2. measure the 40% Black patch: Density 1.22. I
selected 40% by eye, but you can use the densitometer
to find the darkest patch with density less than the
density of 100% Light Black 

3. Measure the density of the next darker patch \ufffd 45%
Black: Density 1.33. Then it\ufffds bit of simple math to
calculate the percentage of black needed to produce
the same density as 100% Light Black. In this case we
get a value of 43.2% Black is equivalent to 100% Light
Black. 
******************************************************

Could somebody, please, explain to me the "simple
math". I am using UT1 inks and Epson R220 printer.

Thanks in advance.
Kemal

--- In QuadtoneRIP@yahoogroups.com, Kemal Delic <kemdel2000@...> wrote:
>
> 
> 
> Hello list,
> 
> I would like to learn how to make QTR curves. I made
> two tests with 100% and 85% ink limit. Now I want to
> do the ink density calibration. Here is the
> explanation in the QuadTone RIP User Guide:
> 
> *****************************************************
> With a densitometer: 
> 
> 1. measure the 100% Light Black patch: Density 1.29
>  
> 2. measure the 40% Black patch: Density 1.22. I
> selected 40% by eye, but you can use the densitometer
> to find the darkest patch with density less than the
> density of 100% Light Black 
> 
> 3. Measure the density of the next darker patch – 45%
> Black: Density 1.33. Then it's bit of simple math to
> calculate the percentage of black needed to produce
> the same density as 100% Light Black. In this case we
> get a value of 43.2% Black is equivalent to 100% Light
> Black. 
> ******************************************************
> 
> Could somebody, please, explain to me the "simple
> math". I am using UT1 inks and Epson R220 printer.
> 
> Thanks in advance.
> Kemal
>

We're looking for where 1.29 would fall given that 40=>1.22 and 45=>1.33

So  (1.29 - 1.22) / (1.33 - 1.22)  gives  0.64    or 64% of the way from 40 to 45.
The formula = (X - low) / (high - low)

Now the interval 40 => 45 is (45-40) = 5.   So 0.64 x 5 = 3.2 
add that to 40 and we have 43.2

This is probably more accurate than you have to worry about.  Guestimating that
1.29 is in the middle but closer to 1.33 you could get away with just saying 43.

Roy

Hello,

I am in  the Ink Calibration Mode and trying to print
the test page, but when I press Print, I am getting
the message  "You must select at least one Curve".

Did I mess up something or something is wrong with 
the QTR?

I am using the newest QTR on PC. Older QTR version 
worked fine.

Thanks,
Kemal

This is a new bug that was discussed a couple of days
ago. Just pick a curve before printing. It has no
effect. It just works around the bug.

Guy
--- Kemal Delic <kemdel2000@...> wrote:

> Hello,
> 
> I am in  the Ink Calibration Mode and trying to
> print
> the test page, but when I press Print, I am getting
> the message  "You must select at least one Curve".
> 
> Did I mess up something or something is wrong with 
> the QTR?
> 
> I am using the newest QTR on PC. Older QTR version 
> worked fine.
> 
> Thanks,
> Kemal
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
>     QuadtoneRIP-unsubscribe@yahoogroups.com
> 
>  
> 
> 
> 


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Thank you Guy,

I can only pick the Printer Name and Printing Model,
there are no curves in this mode.

Kemal

-----------------------------------------------------

--- guy washburn <guido02474@...> skrev:


---------------------------------
This is a new bug that was discussed a couple of days
ago. Just pick a curve before printing. It has no
effect. It just works around the bug.

Guy
--- Kemal Delic <kemdel2000@...> wrote:

> Hello,
> 
> I am in  the Ink Calibration Mode and trying to
> print
> the test page, but when I press Print, I am getting
> the message  "You must select at least one Curve".
> 
> Did I mess up something or something is wrong with 
> the QTR?
> 
> I am using the newest QTR on PC. Older QTR version 
> worked fine.
> 
> Thanks,
> Kemal
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
>     QuadtoneRIP-unsubscribe@yahoogroups.com
> 
>  
> 
> 
> 


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