Paper Developer 'working' capacities for film?

Discussion in 'B&W: Film, Paper, Chemistry' started by rogein, Oct 12, 2002.

  1. rogein

    rogein Member

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    Hi All!

    Could someone tell me is a developer's working capacity is the same for film as it is for paper? For example: according to Kodak, Dektol @ 1:2 has a working capacity of 120 8x10s (photopaper) per gal of mixed developer. Does this also mean that a gal of mixed Dektol has the same capacity if one processed film instead of paper?

    Thanks,
    Roger...
     
  2. Jorge

    Jorge Inactive

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    Well, probably so, if you wish to have crappy negatives. Usually negative developer capacities are calculated by area of film to be developed. For example lets say you are using a developer that specifies 1000 ml for one 8x10 negative, that is 80 square inches, so you could also do 4, 4x5 or 8 to 10 120 rolls. But for paper, the developers are stronger and the compostion as far as anti fooging components etc is different. So, to answer your question you probably could develp more film with the same quantity of paper developer, but I am sure the negatives will have much more contrast, much more grain, and probably will have chemical fog due to the stronger developer. My advice would be to stay away from this idea or to use it much more dilute than what you use it for paper.
     
  3. Robert

    Robert Member

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    Don't some of the more unusual films actually call for paper developers?


    You might want to compare the formulas to get an idea.

    D-72:

    Metol 3grams
    Hydroquine 12 grams

    D-76:

    Metol 2 grams
    Hydroquine 5 grams


    I'm obviously leaving stuff out.

    You've got more then twice the hydroquine and 50% more metol. Maybe use the D-76 guidelines and multiply by 1.5? The simple answer is test it out and get back to us-)
     
  4. Donald Qualls

    Donald Qualls Member

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    Dektol (effectively commercial D-72) was sold as a "universal" developer until at least the early 1970s -- I've developed Verichrome Pan 620 in it at least a couple times, with what I then (around 1972) considered good results; it should be perfectly fine in larger formats, where the grain isn't a big deal.

    It's probably misleading to directly compare capacity against D-76, however, because D-72/Dektol is so fast working in paper strength. Diluted 1:2, Dektol will fully develop a print in about two minutes, and will do the same for film in a similar period -- which is rather on the short side for getting consistent results from one batch to the next. I vaguely recall using Dektol at 1:9, which for paper will give dev times around ten minutes -- and in that dilution, it has enough capacity to develop 120/620 in a plastic tank without requiring extra liquid, though I don't recall if it would work for 35 mm in stainless without requiring use of a two-reel tank and empty reel spacer. D-76 1:9 would require at least 1 liter of working solution for a roll of film, however, to have the 100 ml of stock solution recommended per roll, so it's reasonable to suppose that D-72/Dektol has about twice the capacity as a similar amount of D-76, measured on a stock-for-stock basis.

    From a chemical standpoint, the D-72 has only 50% more metol, but more than twice as much hydroquinone compared to D-76 -- and the hydroquinone (according to Anchell & Troop) regenerates the metol as well as acting as a developing agent on its own. To my eye, this would also tend to support the idea that a given volume of D-72 stock should develop about twice as much film as the same quantity of D-76 stock, and should be used at 2-3 times the dilution in order to obtain normal contrast in a comfortable process time. The results you get from Dektol 1:9 compared to, say, D-76 1:1 are likely to be larger grain, higher acutance, and some reduction in tonality -- but it's certainly worth experimenting with, especially in large format.
     
  5. dancqu

    dancqu Member

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    It is'nt the M/Q ratio that matters when comparing D76
    and D72, it is the sulfite vs carbonate. If you were to
    carbonate D76 I doubt you could tell it from D72. Dan
     
  6. glbeas

    glbeas Member

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    I've used Dektol on my Ektapan before I found a good Rodinal time and I can tell you the Dektol negs look absolutely mushy compared to the Rodinal. Don't know why that is, just means I'll not waste any more film in Dektol unless I'm desperate.
     
  7. mark

    mark Member

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    I used ilford paper developer to develope Kodak Dupe film. I fould I had much better control of the stuff. Once I got the contrast under control it was fantastic stuff. I think I developed it at a ratio as low as 1:40 and as high as 1:100. SInce I could develope that stuff under a red safelight I could control development by watching the negative. It was fun. Dang I miss that job.