I think you are being a bit too critical and cynical.
I applaud Jon's effort though I don't fully understand it - yet!
I have been making digital negatives using my lambda laser printer . The film I have been using is Rollie ISO 25 and the negs were processed in HC110 in rather large trays.
To date I am completely satisfied that this method works for alt prints and silver prints.
In fact I am producing a lith show using the larger lambda negs in contact with the paper.
Input was Cannon Mark 3, output is Ilford Warmtone silver paper in Lith Chemicals.
The resolution is incredible and even looking with a loupe we are seeing no issues.
The calibration process is easy as the Lambda calibrates 21 step wedge before I am good to go.
Right now I am outputting film and testing about 6 Alternative processes and am not using a method of adjusting the curve shape of the file to the final output, I am doing this now by eye and seeing the problems **one neg does not fit all process** but we are at a second stage where I am sending over a master file with curve adjustment that I believe will get us closer.
In May I have the luxury of having Sandy King and Ron Reeder in the same room and I will then see if these guys can look at what I am doing and maybe they will have some adjustment curve suggestions that I can apply.
I am very interested in Mr Cones work , because I suspect that he is reaching into areas I never would have the ability to work with and understand, I am finding that I will be limited to probably 20 inch rolls or 24 inch rolls of Ilford Ortho 25 Silver Film.
But I have the need to make bigger negs and the Piezography K7 maybe exactly what I am looking for to make larger negs.
I am fairly certain that Jon is using a modified form of the regular K7 selenium set for digital negatives. If you look at the picture of the quad file at the end of the link I posted you will see that he calls the ink in the Cyan slot Shade 2.5, and the one in the Magenta slot is called 4.5. This means that they are dilutions, not the regular Shade 2 and Shade 4 in the set for paper.
This implies a dedicated printer for digital negatives since the regular profiles for paper will probably not work perfectly with the divided shades in the 2 and 4 position.
Now, for alternative printing the K7 selenium set is not perfect. The issue is that with the very high UV blocking we need for printing long ES processes like pure palladium and carbon transfer only four or five of the seven inks in the 7600 are useful. The Shade 1 ink, whether matte black of the MPS black, is a much stronger UV blocker than any of the other inks, and the in shades in the Yellow and Light Black slots are almost useless as their UV blocking is so low.
However, not perfect does not mean that the set can not give excellent results because with a good mix of four or five inks it is possible to get very fine grain and good sharpness without any dithering. However, if a printer is going to be devoted entirely to digital negatives there is really no reason to make compromises. Not sure how many want to go that far.
For discussion and information about carbon transfer please visit the carbon group at Yahoo.
If one's going to dedicate a printer to making inkjet negatives, then it would seem to make sense to find an ink that gives the appropriate blocking (and smoothness) for a given printing process, one which allows using as much of the density range of the ink/paper combo as possible. It might turn out, for example, that for UV printing processes, using a super small droplet printer and various dilutions of, for example, HPs green ink would be superior. One thing you quickly learn when making DNs is that the color of ink used can have a big impact on smoothness and lack of artifacts. Mr. Cone's solution sounds sound like a very viable alternative for SG printing.
"Nothing will ever be attempted, if all possible objections must be first overcome." -- Samuel Johnson
(Its OK, I also make colour prints on my printer) I do feel that commercial interests often take the front seat in all sorts of places, including the B&S forum, APUG and Mr Cones blog, which is why this forum has a little more credibility for me. I am shure your system works very nicely and I may use it myself one day, when we know more about the results it produces.
Also, will your profiles be machine readable only or can they be read and altered as a text file or with the QTR curve creation tool? If not, then you are an ink salesman. If you will allow others to improve on your work and alter it (without commercial gain) or learn from it then you may be a printmaker, in my eyes anyway.
Your inkset could be used by many people with widely variable requirements, are your profiles suitable for all print processes out of the box?
Credibility is important on a forum. It takes the shape of knowledge. Certainly this is a very knowledgeable forum.
But, I can't tell if you are actually being serious or being humorous with me.
Yes, the 'profiles' can be read and altered as a text file. Someone is developing an application that alters my profiles and re-linearizes them to his own desired Gamma response. It's a pretty cool idea. Whether he will commercialize on it or not is not in my control. I just put the stuff out there and let people do with it what they may.
But, I don't think that sharing intellectual property is what makes you a printmaker. I believe it's printmaking that makes the printmaker. And further, it's the evidence of that printmaking that makes the printmaker. I believe it's recognizable in a universal way by one's printmaking - what constitutes being a printmaker or not.
Yes to your second question, with the caveat that the alt process must be sensitive to density.
You can read about the three different digital neg processes I designed by clicking here: Digital Negatives on Piezography Blog I think if you read from the back to the front you will get a better understanding of how "profiles" (called Curves in QTR) function - and how they are being used differently in a conceptual manner to arrive at the same conclusion. All three processes are significantly different from one another.
Then, if you want to see how curves are designed in more depth, please click here: Piezography QTR Curves, and you should read from the back to the front.
All of my profiles have been provided free since 2005 when I moved away from proprietary formats, etc
The one thing I sell is ink, which you know that already!
Please, let me know if you have any questions on or off the list.
Jon, just so I can understand: you will actually supply the ink-descriptor (.qidf) file, and that would allow users to modify the linearization portion and/or the gray curve to match their own particular process? Also, with your system, how is the maximum negative density selected (the highlights on the print, of course)? One of the first things I do when I am getting a new QTR profile built is finding the minimum ink density needed to produce a pure white tone on the final print. I was not quite certain from your blog posting how this is determined.
You sound like you're used to having to adjust your QTR curves using the Curves tool in order to produce an acceptable film. There is no compelling reason to change a Piezography curve. The Curve Creator Tool produces a bell shaped curve. Piezography curves are much more complex and have an over-riding factor to lengthen the backslope for under-printing. None of that is possible with the QTR curve. I deliver .quad files with the 16bit data points (256 adjustable points for each curve) - and are adjustable in a spreadsheet or text file - but you would never have to adjust a Piezography curve. With a .qdif format you have three points per curve. They are generalized. Piezography curves are not generalized nor ball park - they are designed to do one thing and do that perfectly. They produce tens of thousands of gray level separations between dMin and dMax. They are linear on the widest range of printer examples (even those with aging heads.) If it does need to be relinearized you can use CreateICC - but that will be a rare case. We can provide a 256 gray patch target for you to print and we can produce a custom. As long as you stay on Pictorico - our linearization will work and produce much higher fidelity than can be achieved with standard QTR workflow.
You actually do not use QTR with Piezography the same way you do with QTR standard curves. All of that headache or challenge or adjustments (whatever they are to you) is not something you need to do with Piezography QTR.
How you find the minimum ink density? That depends upon if you are aware already of what the alt-process or silver paper requires. If you are then it is easy as I name the curves in a way that lets you know what the maximum density they produce are. You can use PDN or Photoshop to refine. But the curves produce a maximum density from 1.20 to 2.00 in 0.20 increments. If you wish to refine that to 1.43 for example - I could just as easily supply that too. I don't charge for Piezography curves unless you need a custom for a media that we have not profiled or was not available when it was released.
But, there is no use using a film other than Pictorico because the others can not support the separation of as many gray values.
Let's say you don't know what the minimum density requirement is because you use color inks rather than a density based system. You could easily determine if your alt process requires over 2.00 or under 2.00 by asking someone who used it back in the day or read a manual that was produced. In Aquatint Photogravure for example, there is ample information to set the dMin and dMax using density. Most processes are under 2.00 - for those you could print out a 21 step with 5 of the curves from 1.20 to 2.00 in 0.20 increments - and determine it that way. Your exposure will only be marginally higher with Piezography because I add 0.05 to the clear film to act as fim base+ fog - but you can easily adjust that out using a spread sheet or text editor.
In the case you are above 2.00 you could use the 3.00 curve and adjust in Photoshop or PDN. Because I produce tens of thousands of gray levels - you will not degrade the alt-process image quality by reducing the dynamic range of the input file in Photoshop. We already exceed what you can produce in the alt-proc.
Does that answer your question?