Piezography Digital Negatives meet Precision Digital Negatives

[donbga]

Well looks like Jon Cone has been busy again. On March 29th he posted a lengthy article on his Piezography website blog announcing that he has worked with Mark Nelson's PDN digital negative system to produce a method of making inkjet digital negatives that can be used to print images on silver gelatin papers (right now a very limited selection) that exhibit no printer dithering. That's quite a claim.

Quoting Mr. Cone,

By marrying Precision Digital Negative system to the Piezography Digital Negative process, one is able to eliminate dithering, increase the output resolution, and have a personal method to linearize silver print or any alternative process. The Piezography Selenium inks and QTR curves are an enhancement to PDN.

Here is the link to the article:

Piezography Digital Negative meets Mark Nelson’s Precision Digital Negative | PiezoPress

Has anyone digested this material yet?

Don

 

[clay]

My quick pass through his article makes it seem to me that he is trying to marry some of the clear advantages of the fine control over individual inks that QTR offers with the automated linearization ability of PDN.

Three remarks:

1) Why not do what many of us are already doing and put the linearization directly in the QTR profile instead of adding another step in the digital negative creation process when you have to curve your image file in photoshop? (correction: on a closer reading, I see that much of the linearization is already embedded in the QTR profiles, and PDN is used for fine-tuning, aka creating 'tweaking' curves)

2) The neutral, or at the very least, consistent Piezography gray inks probably do have some advantages for silver gelatin negatives since you don't have to worry about the contrast alterations that can come about when using colorized negatives in conjunction with VC silver papers.

3) I'm not sure PDN is bringing much to the party that isn't already available for free on the interwebs. It seems to me that it is being primarily used for the tweaking of the profile, but doesn't carry the baton all the way to the finish line and use that information in the profile itself.


The focus of the article seems to be the silver gelatin digineg, and I can see where Piezo inks could offer some serious advantages for that. I wonder how involved they got in the various alternative processes. It appears from the graph that you just sort of pick your maximum density desired and it does the rest. I am not quite clear on how that works. I know from some very recent experience at the Basho workshop that different light sources required vastly different linearization when we were doing palladium printing. The fluorescent UV light required much less shadow density on the negative than did the Amergraph V28 exposure unit. I suppose that is where the PDN tweaking would come into play.


Interesting article, though. The more people out there applying their brains to the problem, the better, in my opinion.