I've read with interest the discussions about using sodium ascorbate with Rodinal. Two questions:

1. Can I mix the ascorbate with water in advance, and store it for later use, or would it deteriorate (so that I need to mix it up just before developing)?

2. I've used Rodinal 1:100 with T-Max 100 with some success, but a 1:50 dilution is suggested in the sodium ascorbate combination. Would a 1:100 w/ascorbate mixture work as well or better than a 1:50 dilution?

Thanks

-- Ben Crabtree (bcrabtree@mn.rr.com), May 09, 2002

Answers

I wouldn't mix pure ascorbate solution unless I use it immediately.

By the way, why you want to use Rodinal? I don't understand! :-) Just get phenidone or metol somehow, and you can easily make carbonate from baking soda. Or even simpler, try Ilfosol-S if you don't want to mess with powders.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 09, 2002.

I used Rodinal 1:100 and it worked fine (rotary processing); I found a speed loss of 1/3 stop using Rodinal w/ascorbate (three different films) while curve shapes and development times remained the same.

For TMX and Acros I just couldn't see much point in adding the ascorbate, even when examining the negs at 30x. While it did significantly improve HP5+ in Rodinal I decided I could "improve" it lots more by just using D-76H 1:3.

Anyway, it dissolves easily so it's no problem to mix on-the-fly.

-- John Hicks (jhicks31@bellsouth.net), May 10, 2002.

"I decided I could "improve" it lots more by just using D-76H 1:3."

Except nightscapes, I always felt that TMX in D-76 1+3 type formulae and Microphen 1+3 tends to be dull, while I like HP5+ in D-76H 1+1 and ascorbate version even more. Do you think rotary agitation makes any difference given appropriate adjustment is made for processing time? I doubt it has any significant effect with TMX, but I thought you might have some insight here.

Also, you once said PMK is a fad these days. Did you have experience or opinion about pyrocatechin based formulae?

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), May 14, 2002.

> Do you think rotary agitation makes any difference given appropriate adjustment is made for processing time?

In making the transition from intermittent agitation to rotary processing I discovered that the curve shapes of Delta 100, Delta 400, TMX, HP5+ and Delta 3200 remained virtually identical.

> Also, you once said PMK is a fad these days. Did you have experience or opinion about pyrocatec

No, but you guys got me to thinking about it in another thread so I just ordered ingredients for Pyrocat-HD to give it a try. I'm often faced with shadow areas in deep shade and brilliant sunlit clouds and what I've read about it indicates it may be worthwhile.

-- John Hicks (jhicks31@bellsouth.net), May 14, 2002.

I have some new data on my site about Pyrocat-HD. See Testing Pyrocat-HD by Clay Harmon. I find Pyrocat-HD to be virtually equivalent to PMK, except that its stain is a different color. The stain color affects how it prints on VC papers, but that normally is not an issue for me.

I do not believe pyro developers are a fad. I have reproduced an article by Bob Herbst (originally published in View Camera), entitled The Effects of Pyro Stain in Platinum Printing, that clearly proves that staining developers (in this case the W2D2 pyro formula) can reproduce a longer tonal range than conventional developers (in this case D-76) for both platinum and silver. The extended tonal range is particularly important for me, since I photograph almost exclusively in Texas, Mexico, and the Southwest, where I encounter bright sun and deep shadows in the majority of my photographs. See particularly Herbst's Figure 4.

-- Ed Buffaloe (edb@unblinkingeye.com), May 15, 2002.

> stain is a different color. The stain color affects how it prints on VC papers, but that normally is not an issue for me.

The stain color is part of what put me off on pyro (Rollo/Leban); I normally print on VC paper and the stain color was rather too much. I don't do platinum although I'm sure it's something I'll have to dabble with at least sooner or later.

> that staining developers (in this case the W2D2 pyro formula) can reproduce a longer tonal range than conventional developers

I agree with that. I got a tremendously long range with Rollo but what bothered me was that all the compression was at the high end when printing the negs on VC paper. Yes I know the solution is to print on graded paper but that's not the way I want to go. What I'd like is something between Rollo and D-76.

One thing I didn't find; do you do an afterbath (developer or Kodalk) or not with Pyrocat?

-- John Hicks (jhicks31@bellsouth.net), May 15, 2002.

When I compared PMK and Pyrocat-HD in the past, I wrote: "Pyrocat negatives print much like PMK negatives on VC papers, but require less exposure on graded papers than similar PMK negatives, because the brown stain doesn’t inhibit the blue light that paper is sensitive to as much as a yellow stain would. Sandy King has stated that alternative process printers who print with UV light sources find their exposure times reduced with Pyrocat-HD when compared with print times from pyro negatives."

I've never used Rollo Pyro, so I don't know it's characteristics. I have found that if I print PMK or Pyrocat-HD negatives on VC paper I need number 3 or 4 filtration to boost contrast in the high values, which in turn increases exposure times. But I've gotten exquisite results with Bergger CB Warm grade 2, Ilford Galerie grades 2 and 3.

-- Ed Buffaloe (edb@unblinkingeye.com), May 15, 2002.