Contact negatives for Pt./Pd. from bw-slides?

[Philipp Grewenbach]

Hello all,

I recently started my adventure into Pt./Pd. printing using the chemistry kit from japanese Ilford (it's Na2 Pt./Pd.)...
So far I have been using digital negatives and got good results regarding the tones, however, I am not completely satisfied due to digital artifacts. So I'd like to switch to a completely analog workflow...
In the past, I tried making contact negatives via interpositives, but without much succes. But what works for me is reversal processing of slide film, so I get bw slides. My question is, would it be possible (and somewhat senseful?) to make enlarged negatives directly from bw slides? My hope is that I can directly enlarge the slides onto contact film and get good results. Would this work?
What could be possible problems?
I plan on using the Rollei Retro 80S as slide film, I previously used it as such with succes (rated at EI 25).
As contact film I have Wephota FO5...

And as a follow-up question, would I have to modify my ratios of Pt./Pd. chemistry?
I use the Na2 process, and for digital inkjet negatives in 8x10 I use 20 drops of Pd., 10 drops of Na2-Pt., and 35 drops of Fer.Ox.... could this work for "real" negatives as well? Or perhaps less of Na2?

Looking forward to helpful responses, best regards, Philipp

 

[Fraunhofer]

I think this will work. I have made enlarged negatives from regular negatives by reversal processing of lith film. Which worked, but was rather fiddly since you need to nail both exposures to get a enlarged negative which prints well. Since you already have slides, the first exposure is taken care of. So now it comes down to dial in exposure and development to match what your Pd print needs. With the Na2 process you have a lot of flexibility to adjust the printing process to the negative you have.

So to answer you last question: if you make an enlarged negative with the same UV contrast as your digital one, then no. Otherwise, yes.

One pitfall I encountered was that I was unable to source lith film which was uniform enough to work for this (basically I had to make several negatives, and chose the best one). Wephota FO5 is supposed to be quite excellent, though.

 

[Lachlan Young]

My question is, would it be possible (and somewhat senseful?) to make enlarged negatives directly from bw slides? My hope is that I can directly enlarge the slides onto contact film and get good results. Would this work?

I've tried it & it seemed to get me to a usable DR for siderotypes etc - I'd start by trying something like Ilford Ortho + or Bergger Print Film in PQ Universal. The two materials I experimented with were Silvermax 100 (135) and Delta 400 (120) which had been run in the Scala process.

 

[jeffreyg]

I have made many enlarged negatives for pt/pd printing using x-ray duplicating film. It is a reversal film and works like making a print with your enlarger. It's a very slow film and should be available from a dental or medical supply.
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http://www.jeffreyglasser.com/

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