If anyone is using or has used Divided D-23, do you agitate in the B bath? If you do agitate, what's your regime?
Thank you.
If anyone is using or has used Divided D-23, do you agitate in the B bath? If you do agitate, what's your regime?
Thank you.
Most 2 bath developers mainly soak in the A bath, but little to no development happens, but the alkali B bath activates the development... Since this process depends on loading up the emulsion with these solutions, agitation is very limited and not vigorous as what is held inside the emulsion is used, rather than the entire bath, and too much agitation would displace the even amount absorbed... My guess is very limited, esp in the beginning, and once in a while during soak...
Not sure about divided D-23, but if you can post the formula, we can check what the baths are exactly...
Steve K
Hi Steve,
Here is the formula I'm using:
Bath A:
7.5g Metol
100g Sodium Sulfite
1L water
Bath B:
2g Borax
1L water
As you can see, the A bath is pretty typical standard D-23 solution. I'm using Borax and in a not so typical concentration as my B bath because I'm trying to tame the inherent contrast of Ektascan B/RA film. My thinking is that since Borax, as an accelerator, produces the lowest contrast of the usual B solutions used that might go a long way to tame x-ray film's contrast. So far, I'm doing 7 mins @ 68F with 30 secs of initial agitation, followed by 10 secs each minute thereafter, in A; and, 3 minutes in B with a 10 sec initial agitation, followed by 10 secs on the minute thereafter.
So far in my testing, I'm getting about 1.98 - 2.02 highlight density which is a tad high for my target density of 1.8 for pt/pd printing. Therefore, what makes the most sense to decrease contrast a bit? Decrease the A time? Decrease the B time? No agitation in the B bath? I'm still working on it, but I thought, maybe, someone on these boards is familiar with Divided D-23 and how changing parameters affects the film. I'm greatly for any insight that might lead me in a direction.
Thank you.
P.S. Yes, I know about the loooong x-ray thread on this forum (and I've contributed to it), but it's hard to find any specific info in there as the search feature doesn't seem to work for me. Or, I'm not doing it right.
I have infra red goggles and have observed development in both D-23 and Divided D-23. I have also observed development in Divided Pyrocat and Diafine.
In truly divided developers like Divided Pyrocat, no development takes place in solution A: only in Solution B. With Divided D-23, development takes place in both solutions. In other words, additional development takes place in Solution B.
For that reason, Divided D-23 is a 2-step developer. Perhaps we could call it D-23 two-step and be more accurate
In the second bath of Divided-23, minimal agitation is necessary, to ensure that development proceeds only where the developer hasn't become exhausted, namely the low values. Too much agitation will spoil the effect. Normal agitation is necessary in Solution A.
Last edited by Ken Lee; 27-Oct-2017 at 13:04.
Ken provides good information, as per usual.
I use a variety of DD-23 to develop my negatives. I agitate for the first thirty seconds and every ten seconds thereafter in both A and B baths. Your method is not out of line.
To reduce contrast, you might try to adjust the amount of Metol in the A bath. I use less, but my B bath is Sodium Metaborate. I have, however, read somewhere that some believe that a lower concentration of Metol is appropriate for standard DD-23.
Thanks all for your input.
Being that I'm developing x-ray film, I'm working under red "safe light" and can see the negative as it develops. However, though I've tried and tried to come to grips with DBI I just can't quite judge proper development visually. That said, the negative coming out of Bath A looks fairly soft, which is as expected, and I think what's happening is that the B bath (accelerator) is pushing the contrast beyond what I need. Therefore, my thinking to shorten the time in B and/or reduce/eliminate agitation. We'll see...more testing to follow.
David - I'll give the Metol reduction some thought. I've read that when Kodak was developing Microdol they discovered that as little as 3g Metol per liter was workable; many use 5g per liter. Using Sodium Metaborate as the B bath is, basically, the same as Borax (speaking contrast here) albeit with slightly more grain. I think either would work fine in this application.
Anyway, if anyone has any futher thoughts I'm listening...
Take a look at this: http://www.largeformatphotography.info/twobath/
Alan, the control for contrast in your specific scenario (development takes place in both baths) is development time in bath A. Varying the type or concentration of the alkali in bath B will not materially alter contrast.
Thank you, David, for pointing me to that article. Lots of good info in there! I've bookmarked it for future reference.
For what it is worth, I divide the Sodium Sulfite from the A bath into the two baths 50/50. That is what David Vestal did with Divided D-76. I surmise that this surpresses development in Bath A. The Sodium Sulfite serves as both a preservative and accelerator in DD-23, so having less accelerator in the A bath would have the impact I mentioned above.
I have successfully developed negatives in Divided D-76H (A bath: 750ml water, 3g Metol, 50g Sodium Sulfite water to make 1L / B bath: 750ml water, 5g Borax, 50g Sodium Sulfite, water to make 1L) which has that 3g/liter of Metol you mention above.
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