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QTR-Quadtone RIP

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Bogged down generating curves/etc for 3000/QuadTone

Bogged down generating curves/etc for 3000/QuadTone

2007-07-04 by David Burren

I've got an Epson 3000 with Selenium-toned QT inkset, and am having trouble getting decent 
results.
I've already set up Epson Photo Quality Inkjet Paper (which I use for drafts in A4 and A3 sizes) 
successfully, but am stuck on getting Hahnemuhle Photo Rag 308 gsm working right.

At times I've ended up with very grainy results, which playing with GRAY_OVERLAP seems to 
help.  But no matter what I do I always seem to get L* values that don't continually get darker 
(especially at the dark end).  I've been reducing and reducing the ink limits (although this 
makes the grain more of an issue) but haven't found the right point yet.  It's a slow process, 
as the prints take quite a while to dry down (not that they seem wet, but the L* values keep 
changing).

If anyone has QTR files for the QuadTone inks on Photo Rag they'd be prepared to share 
(even for different printers: it should give me some hints) I'd be very grateful!
__
David Burren

Re:Bogged down generating curves/etc for 3000/QuadTone

2007-07-06 by David Burren

I've managed to make progress: HPR is now working for me great on the  
3000 with PiezoTone inks.

Part of my problem was probably that I was trying to use the Step-51- 
random target for linearisation, and the differences in the shadow  
areas were very slight.
After stopping and thinking about it a bit, I realised that the  
Step-21x4-random target was a better bet for the linearisation step,  
averaging out scanning errors and having larger steps.

Mind you, I've now defined a Step-51x4-random target and reference  
file which can be used for both steps:
	http://burren.cx/photo/files/step-51x4.zip
Feel free to snag a copy if you think it might be useful to you!


I'm still fine-tuning the 3000 HPR curves a little (aiming to smooth  
out the texture in the mid-tones a bit) but at least I'm moving  
forward and producing prints!

Cheers
__
David Burren

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