Divided D-23 Question

[Alan9940]

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.

[LabRat]

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

[Alan9940]

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.

[Ken Lee]

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 :rolleyes:

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.

[David Karp]

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.

[Alan9940]

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...

[David Karp]

Take a look at this: http://www.largeformatphotography.info/twobath/

[Michael R]

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.

[Alan9940]

Thank you, David, for pointing me to that article. Lots of good info in there! I've bookmarked it for future reference.

[David Karp]

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.

[LabRat]

Good suggestions from everyone!!!

OK Alan, looking at the formula, it is straight D-23, and develops to exhaustion in the B bath, and it seems your problem is the neg Dmax ends up being too high???

One simple solution (literally) might be to change the B bath to a water bath, and let it sit with little/no agitation, or alternate A bath dev intervals with water bath intervals during a tested development, but that might be a PIA, but I have a suggestion;

Since you have been trying two bath developers, and you seem to have tried your own chem mixing from scratch, I once made up a formula that might be the ticket... I had a 35mm project a couple of years ago that I thought a Diafine type two bath developer would be good for, so I priced off-the-shelf developer, and found it silly expensive, so I went on the net to see if there was a "clone" formula I could mix up, and saw there were some variations I could mix...

The alkali in the stock formula seems to be TSP, strong and would probably account for the speed increase it gives, but the variants used Kodalk or borax, but they didn't seem to boost the film speed as much, so I tried the Kodalk (as I had some) at shot about box speed... I had a correct full range development, but the Dmax was lower, but really good shadow detail... The "clone" was a fairly standard PQ developer without an accelerator, but the B bath was TSP, Kodalk, or borax (higher activity and larger grain in that order), but I'm thinking it might be very good for films that produce great highlight densities that need to be pulled down a bit... If you have some hydroquinone, phenidone, borax, and you have the other stuff, that a PQ (or variant) formula might be the answer as they build less density...

The only downside I noticed about this formula was even filtered after use, if the bottle sat for a week or two, there might be a tiny bit of sludge that would collect on the bottom, but I just filtered it off with a coffee filter before use... And I think I used a water bath before processing to remove the AH backing dye, but that didn't cause unevenness to density, so I think OK to use...

Sorry I don't have the formula on hand to post (my lab notes are still in moving limbo), but not hard to find online... I used D-23 a lot of years ago, but I now prefer lower solvent developers used one shot, where I get better edge effects, and don't mind a very fine, but very slightly harder edged grain they give, but even in 35mm, it looks more like "real" film to me (esp in the "digital" age)...

Good luck, and report back what you come up with!!!

Steve K

[Alan9940]

Hi Steve,

Yes, the issue I'm having is that my highlight density is coming in at about 1.98 - 2.10; I'd like to hit about 1.8 for pt/pd printing and/or printing on a paper like Lodima. I think one of the problems I've had with my recent testing is that the ambient temp in my darkroom is so high (live in the desert southwest) that my development times are just too short to control properly. Now that it's cooling down some in the early morning, I'm putting containers of solution outside, and developing early, so that I have a fighting chance of working at or very near 68F. Tomorrow morning I'm trying 5.5 mins in A followed by 3 mins in B with little to no agitation. As you can see, if this time turns out to be correct then any appreciable increase in developer temp would demand a shorter developing time; I always try to stay above 5 mins with any kind of manual development process.

The dance with x-ray film is finding a shorter enough developing time that will hit your target highlight density while still maintaining decent shadow detail. Generally, if I decrease developing time by >20% I'll start to nudge EI downward to ensure that shadow detail. Right now I'm at EI50 which for my outdoor work is about as slow as I care to go for 8x10.

Anyway, x-ray film is cheap (vs regular sheet film) so I don't mind burning up many sheets as I experiment to lock all this down.

Thanks for all your input above.

[LabRat]

Hi Steve,

Yes, the issue I'm having is that my highlight density is coming in at about 1.98 - 2.10; I'd like to hit about 1.8 for pt/pd printing and/or printing on a paper like Lodima. I think one of the problems I've had with my recent testing is that the ambient temp in my darkroom is so high (live in the desert southwest) that my development times are just too short to control properly. Now that it's cooling down some in the early morning, I'm putting containers of solution outside, and developing early, so that I have a fighting chance of working at or very near 68F. Tomorrow morning I'm trying 5.5 mins in A followed by 3 mins in B with little to no agitation. As you can see, if this time turns out to be correct then any appreciable increase in developer temp would demand a shorter developing time; I always try to stay above 5 mins with any kind of manual development process.

The dance with x-ray film is finding a shorter enough developing time that will hit your target highlight density while still maintaining decent shadow detail. Generally, if I decrease developing time by >20% I'll start to nudge EI downward to ensure that shadow detail. Right now I'm at EI50 which for my outdoor work is about as slow as I care to go for 8x10.

Anyway, x-ray film is cheap (vs regular sheet film) so I don't mind burning up many sheets as I experiment to lock all this down.

Thanks for all your input above.

There's little change in shadow detail throughout development (until too much, and fog increases), as development affects the highlights more... (Exposure affects the shadow detail...) Using a formula that allows higher dilutions should allow you to expand your dev time to a comfortable time at higher temps... What other developers have you tried??? (D-23 flattens out way too much diluted, in fact, very diluted it becomes a variation of a Tech Pan developer for taming massive line film contrast... But there's the possibility of the D-25 variation that causes a slight loss of film speed, but finer grain by the addition of the acid salt of sodium bisulfite that might slow processing down if you insist on using this developer...)

The nice thing about the Diafine "clone" above is it is not temp dependent, so you should be fine below 79 (deg)... ;-)

Steve K

[Alan9940]

Hi Steve,

I haven't tried any other divided type developers, but I have tried F76+, Rodinal, and Pyrocat-HD. Most of the aforementioned developers I used on my Jobo in Expert Drums, but I could never really get the style negative I was looking for; perhaps continuous agitation is too much for an inherent high contrast film like x-ray? Dunno. Oh, almost forgot, I also tried 510 Pyro in trays. Though I developed 8x10 film for many years in trays long ago, again, I couldn't get the kind of negative I wanted with that combo.

I you ever come across that Diafine "clone" you keep referencing, I sure would like to get the formula for it. Sure would be nice having something not so temp dependent given that I live in the desert southwest. Heck, during the summer my indoor temps reach >79F!

[Drew Wiley]

Depends on the film, I suppose. I haven't done divided D23 with anything other than thick emulsion films, which are extinct.

[David Karp]

Try dividing the Sodium Sulfite from the A bath into the two baths 50/50. That should reduce development in the first bath.