D76 developer : regular vs. divided versions

[xpista]

Hello,

I decided to mix D76 developer from the raw chemistry and I found two basic variations of this developer - regular and divided.
In past I used the regular D76/ID-11 - so I expect the mixed one to work in the same way (maybe some time adjustments).
But I know nothing about the divided developers.

• What are the advantages of using divided version of D76 to the regular one? (The only one I know of is that the developer temperature is not an issue with the divided developer)
• How do you develop "pushed" film in the divided developer? (Do you develop more in bath A, bath B or both?)

Stefan

 

[Keith Tapscott.]

Hello,

I decided to mix D76 developer from the raw chemistry and I found two basic variations of this developer - regular and divided.
In past I used the regular D76/ID-11 - so I expect the mixed one to work in the same way (maybe some time adjustments).
But I know nothing about the divided developers.

• What are the advantages of using divided version of D76 to the regular one? (The only one I know of is that the developer temperature is not an issue with the divided developer)
• How do you develop "pushed" film in the divided developer? (Do you develop more in bath A, bath B or both?)

Stefan

Not really sure what advantage if any that Twin bath D-76 has over twin bath D-23. Stick with the regular stuff as published, diluted 1:1 (one-shot).

 

[Gerald Koch]

[*]What are the advantages of using divided version of D76 to the regular one? (The only one I know of is that the developer temperature is not an issue with the divided developer)
[*]How do you develop "pushed" film in the divided developer? (Do you develop more in bath A, bath B or both?)
[/list]

The concept behind divided developers is that the emulsion will absorb a certain amount of developing agent in Bath A which is activated when the film is placed in Bath B. Development will continue until all the developing agent is exhausted and then stop. Because of this the user has no control over either film speed (films cannot be pushed) or contrast. It has been said that divided developers do not work well with modern thin emulsion films. I find divided developers to be of limited usefullness.

 

[nworth]

Divided developers should usually be considered to be completely different developers from the single solution versions on which they are based. The results can be quite different, and they may vary among different versions of the divided developer. I general, divided developers are more tolerant of temperature variations than their single solution cousins. They also tend to be more compensating, because the limited amount of developing agent that gets soaked into the emulsion or carried over on the surface becomes exhausted easily in the high density areas. The bromide content of the developer carried over from the first bath is also limited, so the local release of bromide during development in the alkalai becomes important if the second bath does not contain excess bromide. The salt content (e.g. sodium sulfite and or sulfate) of the second bath also has an influence on performance and consistency.

 

[Maine-iac]

I find divided developers to be of limited usefullness.

Agreed for most situations. However, one place I found them to be of enormous usefulness was when I lived in the tropics and could not cool my developer (ambient water temp was 85 F.) sufficiently to avoid grain the size of basketballs. In that situation, divided developers worked great, since temperature is of little consideration in a divided formula. Development stops when its done; if the temp is higher, it stops sooner, and vice versa. But I was able to live with the smaller grain size a lot better. It wasn't fine-grained, but at least tolerable.

While it's true that film cannot be pushed in a divided developer, one can get higher speeds by varying the developer formula.

Larry

 

[kwmullet]

Getting my brain around divided development of film

My own project regarding (there was a url link here which no longer exists) is proceeding at a snail's pace, due to numerous factors including the fact that I've forgotten more than I remember about sensitometry, I don't get fully understand what's going on in divided development, and ongoing time management struggles (*sigh*).

My understanding at this point with divided development is that within sane bounds, neither temperature nor time are useful variables to change. In my own case, I gather that if I use the formula posted to the thread above for at least three minutes for each solution, I've achieved the full effect of each solution.

That being said, would it be fair to say that when doing divided development with film, the exposure index and the dilution of the solutions are the only variables to be adjusted, or is it even less than that? My most recent test run leads me to believe that even though Ansco 130 has a reputation for near-perpetual shelf life, that if I diluted part "A" 1:4 and used a longer development time, it seems to have done very nearly no development.

nworth and Gerald Koch's posts makes me feel like I know a little bit more about what divided development actually is. Am I right in thinking that the entire goal of solution A is to saturate the film with developing agent that will be activated in Solution B? That would seem to explain to me why you don't want to presoak with divided developers. Also, it makes me think that especially since emulsions are thinner nowadays (I"m doing this with Tri-X (bulk load Tri-X 35mm)), perhaps I should soak the hell out of the film in A, like 10-15 minutes to make completely sure as much agent as possible gets loaded up into the film.

I've played with various dilutions of solution B in an attempt to lengthen development time and get the best grain/tonality possible with the developer in question. I'm barely on the edge of a level of understanding here that leads me to believe that's fruitless. If the purpose of B is to activate A, then all I'm doing is emasculating my development, not improving it, right?

If it is the case that in the very most general sense, longer development yields better tonality (uh... maybe I could also state that as more effective compression of a scene's dynamic range into a negative's dynamic range that still has detail in the highest and lowest values), then maybe the only way to lengthen the development is to cool all the solutions, right down to pre-fix rinse, wash water, etc. One of my goals in this project, though, is to avoid any overt temperature control entirely.

I've got a sense here that in my case, the only independent variables are the exposure index I use in the first place and the film I choose.

If I haven't come off as a complete dufus, maybe someone can confirm/deny/expand on these thoughts.

-KwM-

 

[Gerald Koch]

You're right in believing that you shouldn't presoak.

More than 3 to 4 minutes in each bath will not increase density or contrast. *

You can control the contrast by changing the composition of bath B.

Increasing Alkalinity -->
borax <-- Kodalk <-- sodium carbonate <-- trisodium phosphate
Increasing Contrast -->

* Divided developers are not the same as two bath developers. This is not entirely true for divided developers. If bath A is sufficiently alkaline *some* development will take place in this bath. Two bath developers try to prevent this by making bath A slightly acidic.

 

[jim appleyard]

KwM, I don't think you're going to want to soak you film for a longer time than what's called for. In most (not sure about Diafine) divided devs there's some sulfite in bath A to preserve the devving agent. With a time of 10-15 min., I would think that that amount of sulfite *MIGHT* be enough to start some devving.

I've played around with divied devs for a couple of years. I'ts my guess that todays emulsions aren't thick enough to soak up enough of bath A. I haven't lengthened the time in bath A by great amounts, perhaps a minute, but I've also added more metol to it to make it work. In D-23D the formula calls for 5g of metol; I put in 7.5. I've also increased the time from Anchell's suggestions of 3 min./each bath to 4 min in A and 8 min. in B.

I have found that D2D from "The Darkroom Cookbook" works very well as is. This dev calls for hydroquinone and metol in bath A and sod. carb and borax in bath B. I guess this is enough chemistry added all together to make it work.

Hope this helps, J

 

[dancqu]

That being said, would it be fair to say that when doing
divided development with film, the exposure index and the
dilution of the solutions are the only variables to be adjusted,
or is it even less than that?
KwM-

Well an EI is a EI and an ISO is a ISO. Indirectly concentration
can be varied by muti-cycling. I seem to be the only one aware
of the technique. I've read of it in Photo Techniques where Otis
Sprow describes his method. Steve Anchell goes into detail with
an article in Camera and Darkroom.

A bath for single cycle should be rich in developing agent. Multi
cycle may make dilute one-shot A-B developers practical. Either
way B bath is disposable. A little activator goes a long way.

Although 'pushing' is not the word, the EI may be maintained
while high light density kept reasonable. On the other hand N-
development will result in some loss of film speed. N,+ or -,
is not compensating development.

Steve Anchell's article describes several developers, including
a low sulfite high acutance D76, used A-B. IIRC all formulas
include bisulfite to hold back development in bath A. Dan

 

[Gerald Koch]

Indirectly concentration
can be varied by muti-cycling. I seem to be the only one aware
of the technique. I've read of it in Photo Techniques where Otis
Sprow describes his method. Steve Anchell goes into detail with
an article in Camera and Darkroom.

I assume by the term multicycling that the film is returned to Bath A from Bath B. Wouldn't this seriously compromise the life of Bath A since alkali is being introduced into it? The directions with most divided developer formulas make the point of cautioning the user not to introduce any Bath B into Bath A.

 

[dancqu]

I assume by the term multicycling that the film
is returned to Bath A from Bath B. Wouldn't this
seriously compromise the life of Bath A since alkali
is being introduced into it?

Steve Anchell includes a rinse twixt bath B and the
return to bath A. It should be noted though that he has
included in each of the formulas he mentions enough
bisulfite to effectively forestall A bath development.

If though A bath is active AND a compatable alkali is
used in B bath then I see no reason for the rinse. In
fact the cycle might be B to A and back to B.

I've narrowed my interest to one-shot developers.
With those there should not be any restrictions.

Here is Mr. Anchell's "D-76 High Acutance Divided
Developer" compliments of Camera & Darkroom 12/93.

Solution A: ------------- Solution B:
H2O - 750ml ------------ H2O - 750ml
metol - 1.75 ------------ S. sulfite - 46
S. sulfite - 37 ----------- Borax - 30
S. bisulfite - 9 ----------- H2O to make 1 liter
hydroquinone 6
P. bromide .8
H2O to make 1 liter ------ Dan

 

[Gerald Koch]

Agreed for most situations. However, one place I found them to be of enormous usefulness was when I lived in the tropics and could not cool my developer (ambient water temp was 85 F.) sufficiently to avoid grain the size of basketballs.

Have you tried any of the tropical developer formulations. These have the added advantage in preventing excessive swelling of the emulsion. The distortion caused by swelling can cause more degradation of the image than larger grain size.