Digital Negs: Ternary and Other Methods

[mkochsch]

I'm starting a new thread on this because I think it's its own topic. It's for those who've used the ternary system or like me have adapted and created new approaches to solving this problem.

I wrote a brief non-technical article for alternativephotography.com that uses the idea of a ternary graph to determine the appropriate mix of colors that block the most Uv (or other) light. It could easily be adapted to CMY space as well (no black). My RGB approach does, of course, use a little black, but the negativesand resulting prints are as good as any I have seen from other approaches.

http://www.alternativephotography.co...es/art056.html

What exactly is the raison d'etre for PDN using no black ink then? I'll answer my own question. The theory, or part of it, is that black ink by itself was too dense and grainy. Another part is about contrast. The grain arguement may have been truer when PDN was in its infancy than it is today. Printers like the Epson's R-series all print a very fine dot. And if you print with Quadtone Inks that have multiple greys there's no reason why an all black'ish negative can't be used either as some people can attest. I'll agree with you that negatives made using the ternary graph on these printers are as good in most cases, that is, as good for me once I came up with a better method of making the gradient wedge required for curving. The "Posterize" method was too painful and unpredictable. I then adapted to the "Pixelate: Mosaic" filter which worked not too bad. I eventually settled on using a simple black and white stepwedge that went from 0 to 255 in increments in 8 or 16 which I then overlayed with the colour from the original ternary graph (using "Screen" mode with a colour layer) and used this to plot my curves. The example curve you included in the original article was "in the ballpark" but realistically people still need to know how to build a curve to get the best results.
I eventually "evolved" my own method from the ternary system. It was and still is a good idea, but to rival some of the other methods it needs to progress. I think if a new "open source" system was formed using Kevin's script as the curve maker people would embrace a new approach(s), an open approach(s) to making digital negatives.

To build negatives you basically need these things:
i. Standardized printer/photoshop settings.
ii. A method of selecting a starting colour (pre-selection).
iii. A method of linearising the output to the substrate/emulsion/printer combo. (curve).
iv. (optionally) a database which can track the variables and curve versions from the first three steps. A Revision Control System for digital negatives if you will, a la RCS.

[clay]

I'll be glad to contribute to what I can to developing this as a 'open-source' system. I have not tried the automatic curve building routine in Chartthrob yet, but I will see what I can do with it.

I agree that a comprehensive set of steps with some good documentation would be much appreciated by a lot of people. I originally developed this system (I use the term loosely!) so I could teach workshops and give my students Epson2200 curves without running afoul of anyone's proprietary system.

In short, I'm in.

I'm starting a new thread on this because I think it's its own topic. It's for those who've used the ternary system or like me have adapted and created new approaches to solving this problem.



What exactly is the raison d'etre for PDN using no black ink then? I'll answer my own question. The theory, or part of it, is that black ink by itself was too dense and grainy. Another part is about contrast. The grain arguement may have been truer when PDN was in its infancy than it is today. Printers like the Epson's R-series all print a very fine dot. And if you print with Quadtone Inks that have multiple greys there's no reason why an all black'ish negative can't be used either as some people can attest. I'll agree with you that negatives made using the ternary graph on these printers are as good in most cases, that is, as good for me once I came up with a better method of making the gradient wedge required for curving. The "Posterize" method was too painful and unpredictable. I then adapted to the "Pixelate: Mosaic" filter which worked not too bad. I eventually settled on using a simple black and white stepwedge that went from 0 to 255 in increments in 8 or 16 which I then overlayed with the colour from the original ternary graph (using "Screen" mode with a colour layer) and used this to plot my curves. The example curve you included in the original article was "in the ballpark" but realistically people still need to know how to build a curve to get the best results.
I eventually "evolved" my own method from the ternary system. It was and still is a good idea, but to rival some of the other methods it needs to progress. I think if a new "open source" system was formed using Kevin's script as the curve maker people would embrace a new approach(s), an open approach(s) to making digital negatives.

To build negatives you basically need these things:
i. Standardized printer/photoshop settings.
ii. A method of selecting a starting colour (pre-selection).
iii. A method of linearising the output to the substrate/emulsion/printer combo. (curve).
iv. (optionally) a database which can track the variables and curve versions from the first three steps. A Revision Control System for digital negatives if you will, a la RCS.

[Joe Lipka]

mkochsch - If you need any other assistance, I can help. I know what you do works. The wonderful thing about this approach is that it does not depend on a specific printer/ink combination.

[Nathan Jones]

Guys, this is great. This is "the forum" in its highest manifestation: working together to break new ground for the benefit of all. I wish I had something to offer beyond congratulations and encouragement ---but I don't. I'm all ears!

[mkochsch]

May I then suggest the following:

The new system be known as the RAP Negative System.
RAP is a tongue in cheek recursive acyronym for Ratios Aren't PDN Negatives.

~m