QTR: To Linearize or not to Linearize?

jag2x · May 24, 2009

Hi all,

I finally got some MIS UT2 ink to make digital negative with my R1800. This is the first time I've used QTR, and confused about the Linearize window in the Curve Creation tool.
First i'm trying to get my head around making glossy prints with 4 inks. Which I've got on a progressive level of density from using a spyder printfixpro.
Then I printed a 21 step wedge of all 4 inks.
I took note of all the density values of the 21 steps, and inputed them into the Linearize window.
I printed it and its too light in one area or dark in another. The density are all in the wrong place. Isn't the Linerize tool suppose to put them in the right place? What exactly is the Linearize tool used for?

I then decided to not follow the Linearize part of QTR and cleared all the entries in the curve creation. Then I made a gray curve following the Yule/Neilson method. The prints come out great!

Other than the making a gray curve, there has to be a reason to have the Linearize tool? Unless the Linearize tool smoothens the curve? Then from there I would add my gray curve? Am I correct in saying this?

Cheers
Jacek

carioca · May 25, 2009

order of input

jag2x said:
Hi all,

I finally got some MIS UT2 ink to make digital negative with my R1800. This is the first time I've used QTR, and confused about the Linearize window in the Curve Creation tool.
First i'm trying to get my head around making glossy prints with 4 inks. Which I've got on a progressive level of density from using a spyder printfixpro.
Then I printed a 21 step wedge of all 4 inks.
I took note of all the density values of the 21 steps, and inputed them into the Linearize window.
I printed it and its too light in one area or dark in another. The density are all in the wrong place. Isn't the Linerize tool suppose to put them in the right place? What exactly is the Linearize tool used for?

I then decided to not follow the Linearize part of QTR and cleared all the entries in the curve creation. Then I made a gray curve following the Yule/Neilson method. The prints come out great!

Other than the making a gray curve, there has to be a reason to have the Linearize tool? Unless the Linearize tool smoothens the curve? Then from there I would add my gray curve? Am I correct in saying this?

Cheers
Jacek

Jacek,
which way did you input the densitometer readings in the linearizing window?
Printing positives, I have good results inputting from the lightest density value to the most dens. The opposite way of input did not work for me.

On the other hand, when working with digital negs, the input has to be reversed, starting from most dens to the least.

Give it a try.

Sidney

jag2x · May 25, 2009

Hi Sidney,
I inputed starting from highlight which in density terms starts at 0.12, all the way to DMAX of 2.04(Darkest) .
I then went into the Linearize curve, and started from the top left and inputted 0.12 then the next 20 or so numbers till I reached 2.04.

So I didnt really get a good tonality or should I say that the image doesn't look right?
Like I said when I used the Yule/Neilson rules and setup a Gray Curve, it looks great.

I'll give it another go Sidney and see where I get.
Cheers
Jacek

pschwart · May 25, 2009

jag2x said:
Hi all,

I finally got some MIS UT2 ink to make digital negative with my R1800. This is the first time I've used QTR, and confused about the Linearize window in the Curve Creation tool.
First i'm trying to get my head around making glossy prints with 4 inks. Which I've got on a progressive level of density from using a spyder printfixpro.
Then I printed a 21 step wedge of all 4 inks.
I took note of all the density values of the 21 steps, and inputed them into the Linearize window.
I printed it and its too light in one area or dark in another. The density are all in the wrong place. Isn't the Linerize tool suppose to put them in the right place? What exactly is the Linearize tool used for?

I then decided to not follow the Linearize part of QTR and cleared all the entries in the curve creation. Then I made a gray curve following the Yule/Neilson method. The prints come out great!

Other than the making a gray curve, there has to be a reason to have the Linearize tool? Unless the Linearize tool smoothens the curve? Then from there I would add my gray curve? Am I correct in saying this?

Cheers
Jacek

Why do you want to use UT2 and print with only 4 inks for digital negatives instead of using the native inks? I get very smooth negatives and can achieve a dMax > 3.0 using the R1800 Ultrachrome inks and the native Epson driver.

carioca · May 25, 2009

jag2x said:
Hi Sidney,
I inputed starting from highlight which in density terms starts at 0.12, all the way to DMAX of 2.04(Darkest) .
I then went into the Linearize curve, and started from the top left and inputted 0.12 then the next 20 or so numbers till I reached 2.04.

So I didnt really get a good tonality or should I say that the image doesn't look right?
Like I said when I used the Yule/Neilson rules and setup a Gray Curve, it looks great.

I'll give it another go Sidney and see where I get.
Cheers
Jacek

For digital negs, remember highest density value first, then down to the lowest.
Let me know if any difference.

Sidney

jag2x · May 25, 2009

Pschwart, thanks for the info. I haven't even attempted to use the R1800 Ultrachrome inks as yet. I wanted a printer that I can do B&W digital carbon prints as well as digital negs.
With your Dmax > 3.0, what process are you using it for? Also how are your highlights, is there any grain to it?

Sidney, will let you know how I go ..

pschwart · May 26, 2009

jag2x said:
Pschwart, thanks for the info. I haven't even attempted to use the R1800 Ultrachrome inks as yet. I wanted a printer that I can do B&W digital carbon prints as well as digital negs.
With your Dmax > 3.0, what process are you using it for? Also how are your highlights, is there any grain to it?

Sidney, will let you know how I go ..

I make digital negs for both palladium and carbon transfer. Negs are very smooth, not grainy. I have also used MIS UT3D inks in the R1800 for monochrome printing with a custom QTR profile. Using a monochrome inkset means printing is a hassle unless you dedicate one printer to B&W prints and another to digital negatives and color prints.

jag2x · May 26, 2009

Thats what i've got, I have one R800 OEM inks and a busted up R1800 with one ink not working, got only 5 inks firing

Did you make digital negs with the MIS UT3D? How did it compare with the Epson OEM inks?

Is it possible you can send me details on what setup you used to print with the OEM inks?

R Shaffer · May 26, 2009

Ciao Jacek,

I found the information on Paul Roark's website very helpful in trying to understand QTR. He has a good workflow for creating a profile for a 2880 printer, which you may find useful for your R1800. These are for prints, not digital negatives, but that seems to be what your trying to do here.

Dead Link Removed

http://www.paulroark.com/BW-Info/QTR_2200_4K+_MBW-Carb-w7.pdf

I still have not tried using linearization function in QTR for digital negs. I just could not take making any more step wedges, so I made several small prints.
But I'm quite happy with curve I made with Y-N formula for my pd prints.

jag2x · May 27, 2009

Thanks Rob,
I read the pdf, that does make sense.
Linearize it.
Print out the step wedge.
Then create the curve in the Gray Tab.
Then print it all again and Bob's your uncle!

The Linearize presumably smoothens the curve, if there are any huge jumps of density.
Thx

pschwart · May 27, 2009

jag2x said:
Thats what i've got, I have one R800 OEM inks and a busted up R1800 with one ink not working, got only 5 inks firing

Did you make digital negs with the MIS UT3D? How did it compare with the Epson OEM inks?

Is it possible you can send me details on what setup you used to print with the OEM inks?

R1800 has 8 inks, so if only 5 inks are working it's time for a new printer

I can't recall if I tried making digital negs with UT3D.

Digital negs on the R1800: use Premium Glossy Photo Paper media type, Photo RPM, uncheck gloss, uncheck high speed. I create a correction curve and print with ICM and no color adjustment. You get greater dMax with UltraSmooth Fine Art Paper which uses matte black, but the PGPP uses photo black which gives smoother tones and it still gives a good dMax of around 2.7.

QTR: To Linearize or not to Linearize?

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