Arriving at a Density Range ~ Methods

The contrast index curves for this procedure have to do with digital manipulation of the negative in preparation for printing. There is what might be said to be reciprocal methods for that procedure in the digital form. I have written on this subject before; refer to post 8/27/16 ~ "Digital Contrast Index Curves" for the fuller discussion between the two methods of arriving at the same destination.

I am reusing the graphs from the earlier post as it demonstrates visually the crux of the discussion, which is increasing the density range of a negative (digital negative) for printing historical hand coated processes of silver or Pt/Pd. The methods used by Dan Burkholder and Peter Hrhar are represented in the top graph. The method I personally use is represented in the bottom chart. This isn't a good or bad, right or wrong thing. This isn't a matter of who's approach is 'better', but personal approach to arriving at the same destination using different travel methods from personal preference.

Here I won't get into details of practical differences between the two approaches, as that can be found in the earlier post. The testing thus far is demonstrating that both approaches work just fine. The differences have to do with how the final image comes out, according to one's taste. A printed image having gone through both processes, then printed and shown side by side would simply show two identical images, each with a unique look, corresponding to the two methods employed to increase density range. Simple as that. The top method increases the middle tones of the image, altering slightly the lower density ranges Zone 2 & 3, continuing through Zone 6 and even Zone 7. What is not affected by this shift is Zone 8, or Zone 7, fully. Because of this, spectral density is employed; a color layer of a green, flattened, leaving a green negative.

Two Contrast Index Curves; Altered to increase the density range of a digital negative.





































The theoretical differences are visually evident. As I've said, both methods work. My friend PJ followed Burkholder's method, over several days of internet study. His test image was printed yesterday along with my test prints. I can't post his print unless PJ wants that to happen, but I can tell you that the spectral density thing works way better than I could have imagined. Visually, his negative was so thin I wouldn't even attempt a gum print using it. However, his test print was a 12 minute print. My densest negative on hand was a 7 minutes Kallitype print, and that was too long. Compared side by side they visual differences are stark. His negative barely showed densities and mine looked like a Collodian wet plate image. It was stark. His took longer to print. Let that sink in.

Much more will be realized with further testing and printing. It won't take long. Gold chloride toner is on the way, as is enough palladium to tone 100 8x10 prints. The good times are just about to unfold.