[pure-silver] Re: Emulsion hardening for reversal processing of 35mm B&W film


Richard Knoppow wrote:

>     What reversal formulas are you using?

Richard,

The formulas I am using are actually based somewhat on posts you 
made in rec.photo.darkroom over the last few years. However, as a 
first developer I am using a cobbled-together concoction based on 
HC-110B 'spiked' with sodium carbonate to increase activity and 
with sodium thiosulfate as a silver solvent. It works well 
tonality-wise but your and Nick's posts have got me thinking that 
I have maybe brought the alkalinity too high with the quantity of 
carbonate I am using.

My rationale in desiging this developer was to use off-the-shelf 
HC-110 as a starting material and keep the home-brew to a 
minimum. Ilford's documents on reversal processing basically use 
paper developer as a base for a reversal first developer, with 
added thiosulfate as a silver solvent. I was trying to emulate 
this with my HC-110B brew, using extra sodium carbonate to 
compensate for the relative weakness of a film soup vs. a paper 
soup.

My permanganate bleach is of a standard formula. Bleach clearing 
is accomplished with a sodium metabisulfite solution (around 3% 
w/v) and 'redevelopment' uses a thiourea solution made alkaline 
with sodium carbonate. This gives a nice cold brown tone on Pan F 
Plus.

I will try cutting down on the sodium carbonate in my first 
developer and increasing dev time to compensate and will report 
back on the condition of the emulsion. I realize that modified 
D-19 or even Dektol are the standard reversal first dev's (as per 
Richard's many posts on r.p.d) but I would like to get this to 
work, while avoiding an extra hardening step if I can.

Jordan
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