QTR-Quadtone RIP

Hi All,

Getting back into QTR after months on another photographic project.

I am using Print Tool with a 3800 and 9900, also just updated to El Capitan with no problems so far.

After some help from Roy - thank you.

I did my first curve today with the following: i1 Pro (old device UVcut) running i1 Profiler licensed version.

I used: Richard Boutwell's i1-QTR-Step-21x4-random TARGET and his i1-profiler-QTR-21x4-random.txt script.

I printed out the target with Print Tool - No colour Mgmt. left to dry. I loaded the target into i1 Profiler and measured using spot, it went without a problem. Saved the file then proceeded with the Linearisation using Diallo QTR Workflow Level 2.

Again all went OK and the new curve UKpk- 9900- Canson Platine Fibre Rag- Neutral is sitting in the QTR Applications folder and duly shows up when printing from my Quad9900 set up in Print Tool.

I looked at the two graphical displays, one without linearisation and one with. The latter is no where near a straight line, in fact apart from 2/3 tiny shifts in the "L" its the same as the former.

I printed a target - I like the Northlight Images test image that Keith Cooper provides - with my new profile and one with the UKpk-raw-neutral. I cannot see a difference.

Did the same routine and double checked everything, same result.

Any ideas or help would be appreciated - thank you.

Peter

I’m glad you found the i1Profiler target helpful. the .txt is not really a script, and is just the reference file for the 21x4 target. All the scripts are Roy’s creation and included with QTR.

I’ve been thinking about your problem and there might be a few things going on here.

In some rare cases the correction curve from the QTR linearization will make a weird bump where there really shouldn’t be. This doesn’t usually happen with OEM K3 profiles, but is more likely in home-brew k6 profiles.

Take a look at this post: QTR correction curve tool

If you have excel on your computer try putting the measurement data of the RAW profile from the 21x4 target into this spreadsheet template and see how far off linear the raw profile is (pre-linearization). Then take the correction curve string from the spreadsheet and drop it onto the GRAY_CURVE= in the ink descriptor/text file (be sure there isn’t anything in the “linearize= “ line). I’m trying to figure out how to make a photoshop ACV file automatically from these points. It shouldn’t be too hard, but I’m no programmer…

Anyway, that correction curve should get you pretty much dead on before doing the final linearization step.

Another thought might be that after dropping the measurement file onto the linearize-data script there was some problem creating the linearized profile. The graph and the linearize=“……” from the measurementFile-out.text are just the measured L* values and is not the actual linearization. The linearization happens when you paste the string into the text file/profile, resave the text file as pk-9900-profileName-LIN.txt (or something like that), and then rerun the install script for that printer (or drop the profile on the drop-quad script). You should then see output in the terminal window that shows the profile having been linearized—if not then you might get something that says (could not linearize or LAB values are not in order). Then if you compare the two quad files (the RAW and the LIN) they should look different.

Hope that helps,

Richard Boutwell