
Joseph Lipka on Divided D23 I have noticed some talk about D23 developer recently, and it appears that there are almost as many variations of this developer as there are photographers. I have been using D23 as a two bath developer for about ten years. The formula and some other text is included as part of the overall instructions for processing Palladio Platinum Paper made by the Palladio Company in Cambridge, MA. My primary use of D23 is film negatives for platinum printing. I have been using TMAX 400 in 5 x 7 or 4 x 5 sheets. Exposure index for both films has been 400. Here is the recipe: Solution A 750 ml distilled water at 120 F, add 7.5 grams elon (metol) and dissolve completely. Then add 100 grams sodium sulfite and dissolve. Fill with cool water to make 1000 ml. Solution B Dissolve ten grams Kodalk in 1000 ml distilled water at 120 F. This basic 1liter set of chemicals will develop 600 to 800 square inches of film. – 20 5 x 7 sheets. This makes it a "one shot" developer for me. Times and Temperatures The instructions from Palladio advise times between “9 and 14 minutes at 72 F” for Solution A and 3 minutes in Solution B. Time less than 3 minutes for Solution B is not recommended. My Process My developing process is to presoak the negatives for a few minutes, until the sheets move freely in the water. Then I develop in Solution A for 10 minutes. I shuffle sheet film continuously through development. Then in to Solution B for 3 minutes, also continuously shuffled. I try to start both baths at 70 F when I start development, but body heat transferred to the developer usually raises the temperature about 3 or 4 degrees by the time I am finished. After developing, I use a regular acetic acid stop bath, then a hardening fixer. Orbit bath, wash and photo flo complete the process. I asked Rob Steinberg from the Palladio Company about alternative developing times. He gave me the following information, attributed to Tillman Crane. 

Divided D23 Recently someone on the Large Format Forum was trying to find an article (by Jim Veenstra) from an early issue of View Camera magazine on the Divided D23 developer. I happened to have the article, so I shared the formula and developing information with him. While I was at it I read the article again myself. It piqued my latent interest in divided developers, so I read up on them a bit more and did some minor experimentation. This brief article is designed to provide the basic formulas, point out the obvious relationships between them, and provide links to various resources for further information both on and off the web. My first thought when seeing the Divided D23 formula was that it’s not really a divided formula at all (it’s D23 with an alkaline afterbath). This led me to compare D23 with D25 and D76, and the relationships were immediately apparent.
D23 has 7.5 grams of metol and 100 grams of sodium sulfite. That’s it. D25 simply adds 15 grams of sodium bisulfite. D76 reduces the metol to 2 grams, then adds 5 grams of hydroquinone and 2 grams of borax. Solution B for the divided developers is simply 2 grams of borax in a liter of water. There is a variant of the Divided D23 formula by H. Stoeckler, in which he reduces the metol to 5 grams in solution A and increases the borax to 10 grams in solution B. Anchell’s The Darkroom Cookbook gives another variation of the Stoeckler formula, in which solution A has the sulfite reduced to 80 grams and 20 grams of sodium bisulfite is added; he also gives a Divided D23 Variant wherein the metol is reduced to 5 grams (a la Stoeckler) and the borax in the second bath is increased to 18 grams in only 500 ml of water. Joseph Lipka uses a variant that substitutes sodium metaborate (Kodalk) for the borax in solution B.
Supposedly a divided developer has the developing agent in solution A and the accelerator in solution B. But obviously any solution A with 100 grams of sulfite in it has enough alkalinity that it can function as a developer without the addition of further accelerator. So when films are in the above solution A’s, they aren’t just absorbing developing agent and waiting for solution B to provide enough alkalinity to begin developmentthey are developing the film. But solution B is where the compensation comes in. In solution B the developing agent quickly exhausts itself in the high values where the greatest density lies, while the low values continue to develop. So, essentially, you develop in solution A until your high values are almost where you want them, then you place the film in solution B and develop until the shadow values are where you want them. If you are not experienced at development by inspection, you may have to do a little experimenting to get the times just right. Presoaking in water is not necessary. Use your normal agitation method in solution A, and unless you want a very strong N2 contraction, go ahead and give 1015 seconds of agitation per minute (or more) in solution B as well. (For N2, don’t agitate solution B at all.) Increasing the time in solution A raises overall density and contrast, whereas increasing the time in solution B will only raise shadow detail if the film is returned briefly to solution A first. Jim Veenstra gives some suggested developing times in his article, and since the article is so hard to come by I am going to reproduce his suggestions here. You will note he considers that D23 does not require the second bath with TMax films except for an N2 contraction. 

Just to test the above times, I developed two 4x5 pinhole negatives in the standard Divided D23 formula. The film was TMax 400, rated at 320, developed for 7 minutes in solution A and 2 minutes in solution B at 68°F. The results compared quite favorably to my PMK negatives of the same subjects. I plan to use this developer in the future for N1 and N2 contractions. 




