Plus-X in FX-37

Discussion in 'Darkroom Developing and Printing' started by Jorge Omar, Jul 22, 2003.

  1. Jorge Omar

    Jorge Omar Guest


    The massive dev charts lists the time for PX in FX-37 at 1+3 dillution.
    Do someone have the time for 1+5?


    Jorge Omar, Jul 22, 2003
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  2. Hi Jorge,

    My most frequent use of FX-37 is in fact with PX film, which I develop
    with a 1+3 dilution for 5.5 minutes at 68 degrees F. While I have not
    tried 1+5, I think the general formula for dilutions would give you a
    good starting time:

    T(2) = T(1) * SQRT[DilutionParts(2)] / SQRT[DilutionParts(1)]

    In this case,

    T(2) = 5.5 * sqrt 6 / sqrt 4
    T(2) = 5.5 * 2.45 / 2
    T(2) = 6.73 minutes or about 6 min 45 seconds.

    One concern in diluting the developer to this extent is whether you will
    have enough of each of the developer components for the amount of film
    you are developing. Given the very small initial amounts of restrainers
    in this formula, I would wonder whether the typical development curve
    found at 1:3 will be compromised at 1:5. You may want to do some
    experimentation with step wedges to see.

    Francis A. Miniter
    Francis A. Miniter, Jul 22, 2003
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  3. Jorge Omar

    Jorge Omar Guest

    Thanks, Francis

    I've made a guess at 7 min for first test, so I was not very far away.
    Results (daylight photos, both low contrast and high contrast) are
    very promising, wuth good shadow detail at my camera meter @160. I
    don't have a step wedge.

    Just as a note, I've mixed it without bromide - I will have to
    mailorder some, so only benzo at this time. But there is no visible
    (even under enlargement) fog, and fine grain, except for an
    overexposed frame (?).

    Oh, and to my surprise (found it through Google) carbonate plus borax
    gives a lower pH! Why is beyond my limited knowledge of chemistry.


    Jorge Omar, Jul 23, 2003
  4. Fedor
    good mornig,

    interesting formula, do you think that I can use it for HC110 diluitions ?

    for expample: for the diluitions 1+47 i increse the normal time (1+31) of
    50% and the results are good, using this formula the increse is of 23% ??

    do know a formula for the HC110 diluitions ?



    There are no short-cuts to quality. And there is no quick way to achieve
    Fëdor Pavlovic', Jul 23, 2003
  5. Jorge Omar

    piggy Guest

    HI Francis!

    Do you know the some formula for three bath developer?

    this formula assumes that the amount of solution A is the same one,
    and that changes only the amount of B solution (water).

    What succeeds in a bath with 3 solutions? if i want to increase the
    amount of first or of the second one?
    There is a way in order, as an example, to compensate the times of the
    pyro? from 1:2:1000 to 1:4:100 or 2:1:100?

    thanks in advance
    piggy, Jul 23, 2003
  6. Jorge Omar

    Jorge Omar Guest

    I don't think it will work with higly dilluted HC-110 (beyond dillution B).


    and check the timings for 1+63 (warning: times are for 24 deg C).


    Jorge Omar, Jul 23, 2003
  7. Yes, I do think it will work for such dilutions. Actually, I
    participated in a thread on that dilution a year ago. See "HC110
    dilution increase - time adj?" from about September 2002. The formula
    takes into account the proportion of developer in a solution available
    at any time for contact with the square surface area of the film.
    Remember, though, it is a starting point. You may have to refine your
    results as the activity of any developer on any film varies from
    whatever general rule you can come up with.

    Francis A. Miniter
    Francis A. Miniter, Jul 23, 2003
  8. Hi PG,

    You have taken me beyond the limits of my knowledge. I will give it
    some thought but you will probably need a more knowledgeable mind than mine.

    Francis A. Miniter

    Francis A. Miniter, Jul 23, 2003
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