Lee,
"Yes, I've also seen the claim that Rodinal is more concentrated, and we touched on that issue in another thread here on APUG,"
After replying here I recalled that debate. Yep.
"but I keep seeing info from Calbe, ORWO, and other places that indicates that Rodinal is less concentrated."
Please, show me a single source that supports this.
No Orwo publication (including "official" and the Fotokino-Verlag books dating from 1952 to 1990) I own or Calbe leaflet (Calbe leaves the customer alone in that regard, they just give mixing instructions, no times) adresses this, they don´t do ANY comparison with Rodinal nor do they actually mention the Agfa product at all.
Until our last debate (and actually still today) you are the only one I met stating that 1+40 corresponds to 1+25.
Which may be perfectly fine for you. But not "im Sinne des Erfinders" and not supported by the official documents and facts (if you allow that ;-). I have learned in the past that dev times are a very personal thing and may not be applicable by others - a friend develops R50 in Rodinal 1+25 for 7:30min@20°C (hand inversion) to a gamma of 0,65 while I target at 0,55 with 7:30min - in Rodinal 1+50!
According to "Agfa Rezepte+Vorschriften", third edition of 1957 (dating to the time when Wolfen and Leverkusen cooperated), 1+40 is the original "standard dilution" for rolling or inversion tanks (120 and 135) and the original pre-Bayer "Agfa Rodinal" (that means pre-war and Wolfen production), 1+20 used to be for trays (both papers and sheets).
Which is in fact identical to what Foma says in regard to their F09:
"Dilution
(sheet films)
1 part of the concentrate + 20 parts of water
(perforated films and roll films)
1 part of the concentrate + 40 to 100 parts
of water"
(From "Lazne_filmy_en.pdf", you can find it at foma.cz)
For a simple check - grab the specsheets and compare the times for a number of films. Take into account that Agfa targets a gamma of 0,65 and applies a slightly different agitation scheme. We´ll have to resort to the Fotoimpex datasheet for R09, which is not supported via sensitometry but was created based upon try&error and allows for a wide margin.
Perhaps we shouldn´t talk about "more or less concentrated", it´s about activity. Both the Rodinal and R09 solutions are over-saturated with potassium salts, there is not much room for higher concentrations. The production doesn´t call for a specified volume of salts but to mix them until a few of the salt crystals stay unsoluted.
As you can see by just looking at the bottle, R09 is "pre-oxidated" and comes with higher impurities while Rodinal is a clear, pale pink solution when it is fresh (and stays this as long as the bottle isn´t opened) and still clear but slightly brown when the bottle is unopened and standing in the shelf for a year or two - lesser impurities from the raw materials and a mixed and filled in protective atmosphere.
"I still haven't had time to run tests, but hope to sometime soon. Have you had time to do a test yet?"
No, not yet, I´m sorry. But I´ll have access to a densitometer in two weeks and got a stash of FP4 strips in the fridge. I´ll do it next week.
With a bit of luck, I already got results somewhere...
"As Gainer has mentioned several other places in APUG, some films just won't go very high in contrast with Rodinal, specifically HP5+, which won't go over 0.65 when developed to completion, don't know about FP4+."
Agfa adressed this differently - they say "not within reasonable time" but changed this once - one edition of the Rodinal spec sheet in 2003 or 2004 included a time for HP5+/1+50, but they returned to a blank "-" with the latest print.
They state for a higher gamma/beta with rotation and give times for that (in "C-SW16-D16.pdf").
I know the fella who did the testing for the official spec sheets and I am pretty sure I can dig out an official statement <in german> from Wolfgang Holz to that issue - he was/is a product manager BW and adressed this in a german forum.
"If you can't get FP4+ to the higher contrast you wish, perhaps that's part of the problem."
Yep. I´ll have to compensate via temperature and/or agitation. Oh, the "higher contrast" I couldn´t achieve was a beta of 0,55 - the film stopped blank at 0,50!
"OTOH, I can easily get Efke 25 to overdevelop in R09."
Ah, those nasty films with low-silver content. ;-)
) I assume and seem to be backed by most of what I read/hear about stand methods, that as little as 2-3 ml is often enough in the high dilutions. Something I will be sure to try, hopefully soon.
