Trying to generate linearisation profiles with QTR: results are worse

[pharmacist]

Yesterday I tried to generate linearisation profiles for ABW on my Epson ET-8550 and SC-P900, but instead of improvement the shadows get crushed instead of improvement.

Not sure what I did wrong:

Scanning the target:

saving results in to Cielab txt file and dropping to QTR-linearize.data.exe to linearize the results and then dropping into qtr-create-icc.exe

converting the file to the generated icc and then assigning gamma 2.2 profile to the picture and printing with the ABW-mode: getting crushed shadows......the original file in ABW printing mode was better.

 

[Ink stained Fingers]

Do you have some function available like the Black Point Compensation - BPC - routine for B/W prints ?

 

[pharmacist]

Do you have some function available like the Black Point Compensation - BPC - routine for B/W prints ?

In the conversion to profile I get this:

engine: I can choose Adobe (ACE) or microsoft.icm and BPC is checked, as you can see. I choose relative colorimetric.

Afterwards I attach the gamma 2.2 profile onto the coverted (with help of the QTR linearisation profile) image and then I use the ABW mode to print this converted image using the same setting as I have printed the target (ABW with rendering intent: dark), but the dark shadows get crushed and without the QTR profile the image looks better when printed in ABW: much more shadow details.

 

[Ink stained Fingers]

The darker ranges of the image just disappear in the dark, I'm not familiar with the specifics of the QTR method and why a separate linearization is apparently needed. Do you have the means to create a B/W profile in another way - ColorMunki or i1Match or ...- and compare the print outputs with those profiles ?

 

[pharmacist]

actually the QTR is a method is to linearise the gradient of the picture, because it is not possible to use profiles in the ABW-mode, so crushed shadows (which otherwise will be uniform dark gray area) can lift up and give much more details.

 

[roncromberge]

I saw yesterday a oldish YouTube video made by printer guru Keith Cooper. And he says bw does not need and shall not use black point compensation. That’s why b&w profiles are linearized.

I hope this is the right video.

Also linearizing is a special function in qtr. and produce table that you use to make a curve correction in photoshop or any other photo editor. And applying it on your photo to print.

Keith Cooper has a lot of info text and videos about black and white printing.

 

[roncromberge]

I did’t read your first post good enough.

By my knowledge is ABW a printer profile less driver. And profile less! Epson calculate from the picture and there knowledge of their proprietary inks. The right print. According of Keith is The b&w print made with abw very good! But when you do not use the proprietary inkt abw can be very bad.

 

[pharmacist]

Dag Ron,

I am using aftermarket Inktec Powerchrome K3 in in my Epson SC-P900 and the ABW-mode is very good with this aftermarket ink. Some output as Epson's original ink. I have tested this previously in a post last july in 2024. The reason I want to try the QTR linearisation method is to improve the details in the dark shadows. It is not a real printer profile but it changes the image itself in order the ABW-mode will print more details in the dark shadows.

 

[roncromberge]

Dag Ron,

I am using aftermarket Inktec Powerchrome K3 in in my Epson SC-P900 and the ABW-mode is very good with this aftermarket ink. Some output as Epson's original ink. I have tested this previously in a post last july in 2024. The reason I want to try the QTR linearisation method is to improve the details in the dark shadows. It is not a real printer profile but it changes the image itself in order the ABW-mode will print more details in the dark shadows.

Yes i know.
The only thing you create is a tone curve you have to apply as last step in your photo editing process.

When bought my epson p900 a few years ago. (When my Canon iPF 5100 printer died. ) i had the change to go to qtr-rip for my 'antieke foto' with printed A4 and bigger negatives to exposed with UV-light. i bought the expensive program from richard boutwell. to prepare the negatives and make the prints. Sadly i never got the hang with it. and stopped. And dedicate my self to only digital photos and prints.

Perhaps one day who knows, and then ...