QTR and 2400--Thanks! (and a couple questions)

[slr]

Hi All,

I just wanted to say thanks to everyone who has shared information regarding digital negs and QTR profiles!! I read with great interest the thread in which Clay helped Sean, and I gleaned a lot from it. I used an approach based in part on the discussion in the thread (using Excel to smooth the curve), and in part on Ron's book (deriving a profile from scratch).

I first started with the freebie that Clay posted for the 2400. After commenting out the gray curve data I had a tough time setting the contrast range, and I also had to print much much longer than my 8' black time. Ultimately I kept reducing yellow to get close to paper white at step zero, then worked with boost while also pumping some LM and LC into the shadows. Any ideas why that freebie curve wouldn't be closer for me out of the gate? I thought possibly a difference between our light sources. I did try it on Crane's diploma, by the way (the paper it was targeted for). At any rate, I learned a ton about pushing ink around with QTR. It took me 7 printings of the stepwedge, so it will be a while before I can do it as efficiently as some others who help out here!

I had created a profile earlier, but would sometimes get unexpected results when printing. I plugged my gray curve data into the spreadsheet I downloaded here and sure enough, there was an ugly bump. Once smoothed out, the new neg makes a perfect print. That's a good tool, and I hadn't considered using Excel for such a purpose.

This profile works equally well on Platine and Crane's diploma. I didn't really expect that it would, but was pleased to see that it does. If anybody is interested in seeing my profile let me know and I'd be happy to post it here. It was created for pure pd with no restrainer on Arches Platine, (though not on pictorico) and may serve as a starting point for another brave soul.

Thanks again!

Regards, Rob Shepherd

 

[clay]

I'd like to see the profile. I am finding that there are enough process variables in the printing stage between people that make it difficult to have a universal works-for-everybody curve. For instance, I am printing with an Amergraph ULF28, and use 4g/100ml of oxalic acid in my ferric oxalate. I think both of these things may be allowing me to get a faster (and thus lower contrast) print than someone using a fluorescent light box for instance.

But I am glad you got it to work. I think the real strength of the QTR approach is that you can see exactly how the driver is laying down ink and control it. Once you have a smooth curve in conjunction a functioning printer, printing happiness is just around the corner.

Hi All,

I just wanted to say thanks to everyone who has shared information regarding digital negs and QTR profiles!! I read with great interest the thread in which Clay helped Sean, and I gleaned a lot from it. I used an approach based in part on the discussion in the thread (using Excel to smooth the curve), and in part on Ron's book (deriving a profile from scratch).

I first started with the freebie that Clay posted for the 2400. After commenting out the gray curve data I had a tough time setting the contrast range, and I also had to print much much longer than my 8' black time. Ultimately I kept reducing yellow to get close to paper white at step zero, then worked with boost while also pumping some LM and LC into the shadows. Any ideas why that freebie curve wouldn't be closer for me out of the gate? I thought possibly a difference between our light sources. I did try it on Crane's diploma, by the way (the paper it was targeted for). At any rate, I learned a ton about pushing ink around with QTR. It took me 7 printings of the stepwedge, so it will be a while before I can do it as efficiently as some others who help out here!

I had created a profile earlier, but would sometimes get unexpected results when printing. I plugged my gray curve data into the spreadsheet I downloaded here and sure enough, there was an ugly bump. Once smoothed out, the new neg makes a perfect print. That's a good tool, and I hadn't considered using Excel for such a purpose.

This profile works equally well on Platine and Crane's diploma. I didn't really expect that it would, but was pleased to see that it does. If anybody is interested in seeing my profile let me know and I'd be happy to post it here. It was created for pure pd with no restrainer on Arches Platine, (though not on pictorico) and may serve as a starting point for another brave soul.

Thanks again!

Regards, Rob Shepherd

 

[slr]

I'd like to see the profile. ... print than someone using a fluorescent light box for instance.

Hey Clay,

Yes, I'm using BLB tubes. I've read a lot about how well these do or don't work. But I've been making great prints with them for a number of years now. Just out of curiosity, you might try printing something small with my profile on a 2400. I suspect it will come out overexposed.

I have a friend in town who is also just starting to go down the QTR path with some of his pt/pd work. I'm going to share my profile with him, and I'll let you know how it goes. The only thing different between our workflows are the lights. He's also using a Mac and I'm on a PC, though I don't think that variable will come into play. All else (paper, film, printers, inkset, chemistry) are the same! To my way of thinking, he and I ought to be able to share profiles. We'll see. If so, he'll be two clicks away from stepwedge heaven.

I've attached my profile to this post.

Thanks! -Rob