Divided Development, B&W or color
I have spent years experimenting with various B&W formulas, published and my own creations. My gosh, who wouldn't want a developer that was film, time, or otherwise so compensating for every situation? But truth be told, I NEVER got one that worked well. Either thin negatives or large grain. Many say that is because modern films aren't like those of 80 years ago. Whatever the reason, forget it.
Thats B&W! Imagine the complexity times ten or twenty for color. Patrick Dignan published a formula for divided development way back when. I've never tried it, but I've never seen anyone on this or other forums claiming "Eureka!" I do not recall one instance of his formula working.
You are almost 100% correct. Where there is a slight difference in my observations and yours is that a divided developer for B&W is possible, but it must be individually tailored for each and every film due to Silver Halide type, emulsion thickness and etc. This is a painful and tedious task and therefore has never really been made popular. But yeah, you got it. And, color is worse!
Dear PE: Since we "Almost" agree, there is surely hope for peace in the Middle East! Glad we are on the same side ("almost") for once.
The lure of divided development is a sweet song, but as we both now know, it's just not practical. Wish it were other wise.
Now,we agree 100%.
Peace in the middle east is sadly not as easy to achieve.
I'm confused about your B&W comments, since Diafine seems to have a wide following and appears to work for many films. What am I missing?
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Nothing to be confused by. They just don't work very well with modern films. Negatives tend to be thin. Although it's been a couple of decades or more since I used Diafine, I've mixed my own two baths for the same period of time. I've used other people's formulas and made up my own.
Originally Posted by chuck94022
Some people have had decent results by overriding the whole intention of divided development. I.e., keep the film in the first bath longer. The pH is not neutral or low, the sodium sulfite does cause development. If you use a longer A bath, you are right back to time and temperature controls. I've acidified the A bath so no development would take place, used sodium carbonate in the B bath, and IIRC, got very thin negatives. Diafine and all others do develop in the A bath.
Also, I never found the grain to be fine, and it theoretically wouldn't be given the chemistry.
Let me give you an example. Film "A" has 300 mg of gelatin per square foot and 300 mg of Silver Halide. Film "B" has 600 mg of gelatin and 300 mg of Silver Halide in the same area. Now, film "B" will absorb 2x more solution 1 than film "A" and therefore will have that much more to carry into solution 2. You therefore get more development with film "B".
In this case, film "B" might be an old film and "A" might be a modern film, as per Paul's example above. And so, you have to either accept thinner negatives from film "A" or adjust solution 1 or 2 for these new conditions.
The fact that you do not observe it may only mean that you have not done side by side comparisons and / or, you are getting less than optimum result.
For this very reason, divided B&W developers never were really commercialized by EK, Fuji or Ilford.
BTW, the Wikipedia article is incorrect. It implies that commercial processing is done with a 2 bath developer. This is not so.
Dignan did his work with early C-41 films. He did it correctly, using proper sensitometric and color control tools, and got a developer that worked decently and got many excellent reviews at the time. Although that developer tended to have the advantages of a black and white divided developer, it was still quite fussy about composition, times, and temperature. The reference the OP gave showed pictures made with a modified formula which really looked pretty bad, with magenta highlights (not shadows). Scanned postings are always difficult to judge, in any case. The deviations from the prescribed recipe may be part of the reason they look so bad. the formulas always were fussy. We need to note here that color films have changed a lot since Dignan did his work. The changes were calibrated for standard C-41 processing, not for Dignan's soup. The two bath solution may not work as well with these modern films as it did with the early films he used.
Dignan NCF-41 Divided Color Negative Developer
For C-41 films
Water 800 ml
Sodium bisulfite 1 g
CD-4 11 g
Sodium sulfite (anh) 9 g
Water to make 1 l
pH at 75F = 6.5
Water 350 ml
Potassium carbonate 53 g
Potassium bromide 500 mg
Benzotriazole 2 mg
Water to make 1 l
pH at 75F = 11.8
Treat film in prebath at 75F for 3 minutes. Drain for 15 seconds. Treat in activator at 75F for 6 minutes in tank, with continuous agitation for the first 15 seconds and one inversion every 15 seconds thereafter. Treat in activator at 75F for 5-1/2 minutes in drum processor. Provide a 15 seconds drain after the activator and before the stop bath. An 87 g /l sodium bisulfite stop bath at pH 4.8 was recommended.
Ref: Dignan Photographic Newsletter, September 1979
And IIRC, Pat did that with just one C41 film, not several. Also, today's C41 films are very very different in composition including emulsion types and etc.
Yes, I talked to Pat about this and many other projects. At that time, he had a working color paper developer using CD4 and I told him what my dye stability tests looked like. He backed off.
Point is, unless you do a lot more tests than usual for APUGgers, then you run the risk of error. In that formula, maybe Portra 160 might work but Portra 400 would fail, or vice versa. IDK. Maybe neither would work. And Ektar would be a pain with its thin structure and 2 emulsion types.
Oh well, have fun.
I experimented with Dignan's divided developer several years ago and got terrible results with Konica and Kodak films (Portra 160NC was the worst) while Fuji films fared much better with the best results with Pro 160S. The 160NC images were extremely thin with a very yellow mask while the Pro160S was almost acceptable, but overall contrast was a bit low and cyan contrast low, and this was quite visible in prints with some subject matter.
So, yes, different films give different results. One could probably reformulate it to work better with the different films but it is a sure bet you will always have some crossover, so applications would have to be non-critical. One advantage is cost. Whereas the second bath should be used one-shot, the first bath can be re-used multiple times.