Kodak D23 DEVELOPER
I am an italian architect with the passion for photography.
I use 35mm, 6x7-6x9 and 4 x 5.
My film are Rollei superpan 200 for 35mm and Rollei Tonal 100 for medium and large format.
I love D-23 for developing my film with 1+1 or 1+2 diluition.
The contrast is low, the gray scale is wide but the acutance is low.
For increasing it I have read, in many scripture, is possible to use :1+3 diluition, add 50cc potassium iodide 0.001% and to make an unbroken agitation for the first minute and 5 seconds/3-4 minutes.
Somebody had ever tried to follow this procedure? What are been the results?
Is sufficient increasing the developing time of 25/30% starting from that used for 1+2 diluition (19.30 minutes).
Thanks and sorry for my bad english
Two things are contributing to the low contrast problem. First, Metol is a low contrast developing agent which needs time to work. Second, the higher dilution of 1+2 works to lower contrast. There is nothing wrong with increasing the development time. I would first try increasing times by 15% and then 30% if necessary. You are right dilution will help with acutance. You mention 50 ml of potassium iodide solution but don't mention the total amount of developer solution. Typically 5 to 10 ml is added to 250 ml of developer.
You can also try adding 2 grams of borax to the undiluted D-23. The slightly higher pH will improve contrast without increasing development time.
At higher dilutions, D-23 is highly compensating. It gives very low contrast overall with generally good local contrast.
Given enough time, and given enough sheer volume of developer to be sure it doesn't exhaust, D-23 can offer a full density range. I'm pretty sure that would mean having plenty of developer if it is used very dilute as you say you intend.
At 1:3, which I've never used, for testing, I'd want to have maybe an empty reel for each reel with film in it, and filling the tank right to the top, as a starting strategy for roll film. Some similar plan would need to happen for sheet film. If your subject matter had a lot of high density areas - skies and white backgrounds etc, that would be especially important, since those areas exhaust developer the most rapidly.
All of this is probably a good question to do testing on rather than guessing based on speculations from others.
I've not used D-23 with medium or low-speed films, so this experience may not apply. I have used it diluted 1:3 and 1:4 with 35 mm TriX shot at ISO 400. Using a semi-stand agitation - first 30 seconds constant and then six inversions every five minutes, I wet print grade 3 with 1:3 done 20 minutes at 68 degrees f. With 1:4, the prints were consistent grade 4 but with greater definition. That said, neither gives the same definition as two-bath D-23 as per Barry Thornton.
I have tried to develop a Rollei Tonal 100 4 x 5 with D-23 1+3 + 5cc potassium iodide 0.001% for 32 min. with an unbroken agitation for the first minute and 2 reversal every 3 min.
The result is very good for me: medium contrast, very good definition, high power of compensation and wide tonal scale.
These considerations born only to see my sheets becouse I have no densitomer and I cannot make a prints becouse my darkroom is condemn for the great earthquake of 6 April 2009.
Thank for your suggestions.
Great to see you have had good results from D-23. It's a great developer. I'll have to try it at 1:3 sometime. I would like to hear how it prints for you when you get the opportunity to do prints from these negatives.
Experimenting now with green X-Ray film, it has been noted that D-76 1:3 for 5 mins at 72 degrees is not taming contrast quite adequately. Barring for now the use of Pyrocat HD, would someone know if the use of D-23 would offer some contrast relief? If so, would you place it somewhere part way between D-76 and Pyro? Thank you.
D-23 was designed to give essentially the same results as D-76. Compensating developers are different, and it is easier to get lower contrast with them, without as much loss of film speed. I would not consider Pyrocat HD an inherently compensating or low contrast developer, but it can never hurt to try. It is based on Catechol, not Pyrogallol by the way.
Low contrast is a sign of under development. I developed a roll of Tri-X in undiluted D-23 last night for the recommended 7.5 minutes as part of a project. The results were quite similar to D-76 (1+1) for 9.75 minutes, but the grain was somewhat softer and the sharpness was somewhat less. Simple scaling would say that the development time in D-23 (1+1) would be about 10.5 minutes, but the massive development chart recommends 13 minutes. Even undiluted, D-23 shows some decided compensating effects. At 1+3 it is very similar to the Windisch compensating formula, which is well known for massive contractions on the order of N-4 or even N-5. Highlights and upper midtones would be greatly compressed. When diluted, D-23 exhausts quickly, and it should be used as a one-shot at dilutions greater than 1+1.