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Thread: Developer Dilution

  1. #1
    Raffay's Avatar
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    Developer Dilution

    Hello

    I see a lot of formulas for developers I mean in terms of dilution, I initially thought that it is primarily for saving on developer. However, while I was looking for different films to buy on the internet, some films had instructions like "for better tonal values use 1+4 or 1+10 etc. etc."

    I want to know does dilution affects how the film is finally developed, is there any science behind it?

    Cheers
    Raffay

  2. #2
    Land-Scapegrace Heroique's Avatar
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    Re: Developer Dilution

    Lots of ways to address your question.

    And yes, lots of science, but personal experience & plenty of notes prove best for me.

    One example: For contrasty negatives (imagine a snowy scene w/ evergreens in broken sun), I’ve often used a dilute developer & increased development times to help preserve shadow detail, while also keeping sufficient density in the high values. I usually plan this development process at the time of the actual shot, giving the shot more exposure than I normally would. A search for “compensation development” will generate a lot of useful information about this specific use of dilute developers.

  3. #3
    8x10, 5x7, 4x5, et al Leigh's Avatar
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    Re: Developer Dilution

    One fundamental requirement...
    You must always use at least the minimum amount of concentrate for the amount of film being processed, regardless of what dilution you use. Developer capacity is on the spec sheet, given in "rolls". A roll is one 36-exposure 35mm, one 120 roll, four 4x5 sheet films, one 8x10 sheet film, or anything else that can be proofed on a single sheet of 8x10 paper.

    =====

    Exposure (effective ASA), dilution, agitation, and development time all affect the final results.

    The tradeoffs are different for every film/developer combination.

    If you really want to nail a combination you need to go through the full process calibration used for the Zone System. That's really overkill for most people, but it's there if you want to use it.

    The main factor controlling your results is consistency. You MUST do everything exactly the same every time.

    - Leigh
    If you believe you can, or you believe you can't... you're right.

  4. #4

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    Just a couple of comments to augment the above.

    First, compensating developers are usually weaker (i.e., more diluted) and work to reduce contrast because they exhaust in the denser areas of the negative effectively stopping or slowing down development in those highlight areas, but keep working in the shadow areas, which are less dense. This effect only works if there is enough time between agitations to allow the developer in the denser areas to get used up, so compensating developers are often used together with schemes of reduced frequency of agitation. Some use stand developing (where agitation is reduced to once every few minutes or longer) for extreme compensation. Many "normal" developers can be used more dilute and with less frequent agitation to achieve this compensating effect.

    Some developers, such as D-76, contain a lot of sodium sulfite at full-strength dilution. This relatively high concentration of sulfite acts as a silver solvent during developing. It dissolves some of the developed-out silver and then redeposits it on other silver grains. This has the effect of softening the grain, but reducing acutance of the negative somewhat. Many like the smooth look of solvent developers. Note that the instructions for D-76 say that you should dilute the developer 1+1 if you want less solvent effect (sharper, coarser grain, but more acutance). In this case, the dilution has a direct effect on grain rendition.

    With many developers, diluting has no real effect if you keep the agitation intervals short and extend developing time to compensate. This can, however allow longer development times in cases when full-strength developer would result in uncomfortably short times.

    Finally, I found that diluting some developers can reduce fog a bit with extended development. I've used HC-110 diluted 1+63 from concentrate to get expansions (N+1 and N+2) from T-Max films. For some reason, using the 1+31 dilution seems to fog the base more and affect shadow detail. I'm not sure why this happens.

    Hope this helps a bit,

    Doremus

  5. #5
    Raffay's Avatar
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    Re: Developer Dilution

    I am using D23 at full strength with 5 sec agitation per minute. I think my pictures are not very sharp and are quite high in contrast, what dilution do you guys recommend. Here is a sample:

    http://www.flickr.com/photos/february71/8484796121/

    Cheers
    Raffay

  6. #6
    Resident Heretic Bruce Watson's Avatar
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    Re: Developer Dilution

    Quote Originally Posted by Raffay View Post
    I want to know does dilution affects how the film is finally developed, is there any science behind it?
    If you want to know the science behind film development, there are huge tomes on the subject. Grant Haist wrote the definitive work, Modern Photographic Processing, in two volumes. Took him something like 20 years. Over 1400 pages total. You want detail, this is where the detail lives.

    The quick and dirty condensed version can be had from books like Anchell and Troop's Film Developing Cookbook.

    The super short version is that you increase dilution of developers primarily for two reasons. First is economy -- use only the developer concentrate that you need and no more. Second is time -- more water means longer development times to reach the same density. This is often useful since too short a development time can create uneven development artifacts.

    Years ago I carried out some fairly detailed experiments on my own trying to figure out this very question about dilution. I did this with HC-110 and 5x4 Tri-X, and later with XTOL. What I found about graininess and tonality is that while there is a small effect from changing dilution, it was quite small -- I could just barely see it with a 10x loupe on a light table, comparing films side-by-side. I couldn't see it in a print until 15x which for 5x4 film is a print of impractical size. The difference was that the film grain was a little better formed (a tiny bit bigger, a tiny bit sharper) at higher dilutions, and there was a tiny bit more micro-contrast at higher dilutions. The effects on tonal values were vanishingly small, and certainly not worth the trouble.

    In my work I've found much bigger effects on tonality from exposure and development time. What works for me is to have just enough density in the film to render the tonality I want in the final print, and no more. Years of researching brought me back to the most basic of principles in photography: Expose for the shadows and develop for the highlights. This has been the "secret" of B&W chemical photography for the last 150+ years.

    So, you want better tonality? Control your negative's density by getting the proper exposure and proper development time. There's no magic bullet -- no magic dilution. Just a lot of work learning your process.

    Bruce Watson

  7. #7

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    Re: Developer Dilution

    I'm going to have to agree with Bruce on this one. D-23 is a "soft" developer...maybe the best soft developer ever. You have to adjust your exposure times until you hit the magic that this developer is famous for. For Pan film, use same numbers as D-76 (time) for Ortho, use D-76 numbers for a guide, then inspection. I don't know what film you are using, but the developer is not the problem. Greta Garbo can't be wrong.

  8. #8
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    Re: Developer Dilution

    Quote Originally Posted by premortho View Post
    I'm going to have to agree with Bruce on this one. D-23 is a "soft" developer...maybe the best soft developer ever. You have to adjust your exposure times until you hit the magic that this developer is famous for. For Pan film, use same numbers as D-76 (time) for Ortho, use D-76 numbers for a guide, then inspection. I don't know what film you are using, but the developer is not the problem. Greta Garbo can't be wrong.
    I am using Ilford HP5, FP4, and Kodax TMAX400

  9. #9

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    Re: Developer Dilution

    I'm probably not the best to consult on this problem. I've only shot three brands of film for other than snapshots, for 65 years. Ansco (the best), Kodak, and Arista rdu. I tried a roll of hp-5 once, didn't like it, so never kept at it to get it to work. Never have used T-max films either. I only use Arista edu. ultra 100 because I can't get plus-X anymore. I have heard from friends who use Ilford that they expose hp-5 at 250, and fp-4 at 80 or 64. Kinda the opposite of D-23 is Rodinal. If you can get Rodinal developer, try that and see if you like it better.

  10. #10

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    Re: Developer Dilution

    If your scans look soft, its probably not the developer. Assuming the exposure was in focus to begin with, then the scanning process will expend some of the negatives inherent sharpness. On an epson flatbed scanner a film holder that can be focused and that keeps the negative flat, such as a betterscanning holder or a home made version, helps a lot. Then if you want more sharpness wet mounting may be the way to go. Scanned film usually needs some sharpening in photoshop or some other image editing program.

    David

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