Results 1 to 9 of 9

Thread: two solution D-23 question

  1. #1

    Join Date
    Dec 2007
    Location
    klamath falls, oregon
    Posts
    1,729

    two solution D-23 question

    I've been using D-23 to develop all of my sheet film for the past year or so. I recently encountered a posting of a few articles by Barry Thornton, and in one of them he discusses two-bath D-23 and gives three recipes. I've tried his recipe for several rolls of 120 film now, and am quite happy with the results.

    My question is this: He mentions in the article that one should drain off, but save, Bath A before putting in Bath B, but then he never says what to do with the drained off Bath A! (Or, for that matter, the drained off Bath B.) Does anyone have experience with this? For one roll I tried mixing new Bath A and B with the old, 50-50, and to my not-very-sophisticated eye, the results looked OK, but maybe not as good as when both solutions are fresh.

    I have some very important rolls that I am developing right now, and will definitely use fresh solutions for all of them!

    Thanks in advance for any light anyone can shed on this!

    Gregg

  2. #2

    Join Date
    Jun 2017
    Location
    West Coast
    Posts
    2,132

    Re: two solution D-23 question

    Quote Originally Posted by h2oman View Post
    I've been using D-23 to develop all of my sheet film for the past year or so. I recently encountered a posting of a few articles by Barry Thornton, and in one of them he discusses two-bath D-23 and gives three recipes. I've tried his recipe for several rolls of 120 film now, and am quite happy with the results.

    My question is this: He mentions in the article that one should drain off, but save, Bath A before putting in Bath B, but then he never says what to do with the drained off Bath A! (Or, for that matter, the drained off Bath B.) Does anyone have experience with this? For one roll I tried mixing new Bath A and B with the old, 50-50, and to my not-very-sophisticated eye, the results looked OK, but maybe not as good as when both solutions are fresh.

    I have some very important rolls that I am developing right now, and will definitely use fresh solutions for all of them!

    Thanks in advance for any light anyone can shed on this!

    Gregg
    Hi Gregg.
    There is definitely a capacity of these solutions. B exhausts before A, but I usually replace both at the same time. I understand that 1 liter of each solution has a capacity of 600-800 square inches of film. (20 sheets of 5x7 film, approximately 10 sheets of 8x10, etc) I've read that some people use Bath B only once per film and discard it, but I haven't had any issues reusing it, as long as I don't go beyond its capacity.

    Its simple: both baths (A and B) got back into their bottles to use again, assuming they still have some capacity left in them. DO NOT allow solution B to get into solution A, or you have to dump it and make fresh. If I use the chemistry once, for 2 or 3 sheets of film and then don't use it again for a few weeks, I opt to make fresh solutions rather than take a chance on their viability after sitting for weeks.

    So basically, you reuse both A and B to a limit of about 600 square inches of film. I make only 500 ml of each when I make this developer, and a few days ago I developed 5 sheets of 8x10 film in it, and then dumped it to make new. If I observe that the baths are getting discolored or murky when I've finished developing some film, even if I haven't reached the capacity limit, I discard them and make fresh. Its ridiculously cheap to make a liter of each, so why bother taking chances on the capacity limit?

    Have you seen this document?
    https://unblinkingeye.com/Articles/DD-23/dd-23.html

  3. #3

    Join Date
    Sep 2014
    Location
    Montreal, Canada
    Posts
    1,995

    Re: two solution D-23 question

    If you want the most consistency, both solutions should be used one-shot (ie don’t pour A or B back into the stock solution bottles after use).

    Quote Originally Posted by h2oman View Post
    I've been using D-23 to develop all of my sheet film for the past year or so. I recently encountered a posting of a few articles by Barry Thornton, and in one of them he discusses two-bath D-23 and gives three recipes. I've tried his recipe for several rolls of 120 film now, and am quite happy with the results.

    My question is this: He mentions in the article that one should drain off, but save, Bath A before putting in Bath B, but then he never says what to do with the drained off Bath A! (Or, for that matter, the drained off Bath B.) Does anyone have experience with this? For one roll I tried mixing new Bath A and B with the old, 50-50, and to my not-very-sophisticated eye, the results looked OK, but maybe not as good as when both solutions are fresh.

    I have some very important rolls that I am developing right now, and will definitely use fresh solutions for all of them!

    Thanks in advance for any light anyone can shed on this!

    Gregg

  4. #4

    Join Date
    Jun 2017
    Location
    West Coast
    Posts
    2,132

    Re: two solution D-23 question

    Quote Originally Posted by Michael R View Post
    If you want the most consistency, both solutions should be used one-shot (ie don’t pour A or B back into the stock solution bottles after use).
    Yes, not a bad idea if you want the exact same results with every sheet of film you process. DD-23 is very cheap to make, so its very affordable as a one shot developer. Still, I process at least 2 or 3 sheets in a bath before discarding it. I have not observed any change in results by doing so.

  5. #5

    Join Date
    Sep 2014
    Location
    Montreal, Canada
    Posts
    1,995

    Re: two solution D-23 question

    I agree, Paul. Depending on the volumes of stock solutions you begin with, from a practical perspective you can definitely re-use to varying degrees before you actually notice any difference.

    Solution A is a functional metol-sulfite developer, so re-use without replenishment will result in a gradual decline in activity. Again, depending on the initial volume, it will take some amount of re-use before you notice anything.

    Solution B is just an alkali, with decent buffering in the case of most two-solution D-23 type developers. However as you re-use it, small amounts of both exhausted but also non-exhausted solution A will gradually build up and as this happens solution B will slowly start to become a functioning developer. Here again it will take some time before you notice any difference.

    As always there is a pretty significant amount of allowable slop in darkroom processes before you actually see something vs sensitometer measurement.

    Quote Originally Posted by paulbarden View Post
    Yes, not a bad idea if you want the exact same results with every sheet of film you process. DD-23 is very cheap to make, so its very affordable as a one shot developer. Still, I process at least 2 or 3 sheets in a bath before discarding it. I have not observed any change in results by doing so.

  6. #6

    Join Date
    Dec 2007
    Location
    klamath falls, oregon
    Posts
    1,729

    Re: two solution D-23 question

    Thanks for the reference, Paul, and good, conservative advice, Michael.

    In the document Paul referenced it says this: "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 development--they are developing the film." I can verify this via a funny story.

    My level of expertise and experience are pretty low, so this two-bath thing is quite an adventure for me. In the past, when developing roll film, I've agitated in a canister, then completely removed the spool to pass it through a stop bath (in a yogurt container), then put it in another canister for fixing, so I had never poured solutions into or out of a canister. When testing on some rolls I shot around the house, I was once pouring out solution A with the lights on, and the whole lid fell off! I scrapped that test at that point, but looked at the film and saw that quite a bit of development had taken place in Bath A.

  7. #7

    Join Date
    Dec 2007
    Location
    klamath falls, oregon
    Posts
    1,729

    Re: two solution D-23 question

    Not that either solution is all that hard to make, but B is definitely easier (only one chemical, and I find that it dissolves easily without warming the water), so mixing it fresh all the time seems like a good option.

  8. #8

    Join Date
    Jun 2017
    Location
    West Coast
    Posts
    2,132

    Re: two solution D-23 question

    Quote Originally Posted by h2oman View Post
    Thanks for the reference, Paul, and good, conservative advice, Michael.

    In the document Paul referenced it says this: "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 development--they are developing the film." I can verify this via a funny story.

    My level of expertise and experience are pretty low, so this two-bath thing is quite an adventure for me. In the past, when developing roll film, I've agitated in a canister, then completely removed the spool to pass it through a stop bath (in a yogurt container), then put it in another canister for fixing, so I had never poured solutions into or out of a canister. When testing on some rolls I shot around the house, I was once pouring out solution A with the lights on, and the whole lid fell off! I scrapped that test at that point, but looked at the film and saw that quite a bit of development had taken place in Bath A.
    As was pointed out in the referenced article, the truth about DD-23 is that the Bath A is a competent, soft developer used on its own (I've used it as a standalone developer many times, and it works well), but by using a shorter time in A (shorter than needed for a "properly developed" negative) and putting it into an accelerator (Bath B) for 3 minutes, you get the modest compensating effect, where highlights are restrained and shadow information gets a boost. Its the accelerator boost that is the real value in using D-23 and a divided (2 bath) developer.

  9. #9

    Join Date
    Sep 2014
    Location
    Montreal, Canada
    Posts
    1,995

    Re: two solution D-23 question

    Here is specifically how a a two-bath metol-sulfite (D-23 or similar) process works.

    1. Bath A is a fully functioning complete developer. The amount of development/time given in bath A is the primary determinant of the final gradient/contrast of the negative. Usually full development is not given in bath A.

    2. Bath B is typically more alkaline than bath A, which accelerates the rate of development of the remaining solution A absorbed in the emulsion. Development to exhaustion (depletion/diffusion) in bath B completes the process but with some special tone reproduction characteristics:

    i) Full or maximum emulsion speed is achieved without a significant increase in overall gradient
    ii) Overall shape of the characteristic curve tends to straighten (shorter toe, shorter shoulder, longer straight line)

    Here is a visual example using FP4+. In this case the first bath was Stoeckler which is very similar to D-23:

    Click image for larger version. 

Name:	fig2.jpg 
Views:	15 
Size:	47.7 KB 
ID:	221536

    Quote Originally Posted by h2oman View Post
    Thanks for the reference, Paul, and good, conservative advice, Michael.

    In the document Paul referenced it says this: "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 development--they are developing the film." I can verify this via a funny story.

    My level of expertise and experience are pretty low, so this two-bath thing is quite an adventure for me. In the past, when developing roll film, I've agitated in a canister, then completely removed the spool to pass it through a stop bath (in a yogurt container), then put it in another canister for fixing, so I had never poured solutions into or out of a canister. When testing on some rolls I shot around the house, I was once pouring out solution A with the lights on, and the whole lid fell off! I scrapped that test at that point, but looked at the film and saw that quite a bit of development had taken place in Bath A.

Similar Threads

  1. Pyrocat HD solution B question
    By _tf_ in forum Darkroom: Film, Processing & Printing
    Replies: 10
    Last Post: 16-Oct-2021, 22:31
  2. Question about Ammonium thiosulfate 60% solution
    By LFLarry in forum Darkroom: Film, Processing & Printing
    Replies: 8
    Last Post: 3-Nov-2018, 15:48
  3. Pyrocat HD question: Solid precipitate in Solution B?
    By Robert Langham in forum Darkroom: Film, Processing & Printing
    Replies: 18
    Last Post: 7-Mar-2017, 07:50
  4. PMK solution B
    By kev curry in forum Darkroom: Film, Processing & Printing
    Replies: 12
    Last Post: 12-Mar-2013, 09:44
  5. HC110 converting solution A to solution b
    By spgreene in forum Darkroom: Film, Processing & Printing
    Replies: 6
    Last Post: 21-Oct-2006, 07:39

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •