Adjusting development for temperature

Discussion in 'Darkroom Developing and Printing' started by sometime.photographer, Apr 6, 2008.

  1. Given that the basement is still coolish from the winter, what would
    be the best development time factor for D76 at 60 deg F (15 deg C)?

    An experiment with a roll of film at 1.66x recommended time yielded a
    rather razor thin negative, though the film had been sitting in the
    camera a year or so. This time factor was taken from an old Manual of
    Photography by Focal Press, but it was not specific to D76, just part
    of a table of suggested factors at a given "temperature coefficient".
    The Manual refers to temperature coefficient for developing agents and
    listed a table of factors for a coefficient of 2.75. Here is a part of
    the table:

    Temp: Factor
    15 deg C: 1.66
    17 deg C: 1.35
    20 deg C: 1.00
    22 deg C: 0.82

    I am just getting back into B&W film again, after a long hiatus. Any
    comments on an appropriate development time for the next roll?

    Some further searching on Google found the following link with some
    more details:

    "A characteristic, named the "temperature coefficient," has been used
    as the quantitative measure of the change of activity. This is defined
    as the ratio of
    the development times required to produce equal density at two
    temperatures differing
    by 10°C., which is, of course, a difference of 18°F. The values
    obtained range from 1.3 for metol alone, through 1.9 for pyro and
    metol-hydroquinone combinations, to 2.5 for glycine."
    from: http://www.questia.com/PM.qst?a=o&d=97634617
    (in referernce to the book: Handbook of Photography by Keith Henney,
    Beverly Dudley; Whittlesey House, 1939.)

    Thanks for any comments.
     
    sometime.photographer, Apr 6, 2008
    #1
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  2. sometime.photographer

    Andrew Price Guest

    Andrew Price, Apr 6, 2008
    #2
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  3. Given that the basement is still coolish from the winter,
    what would
    be the best development time factor for D76 at 60 deg F (15
    deg C)?

    An experiment with a roll of film at 1.66x recommended time
    yielded a
    rather razor thin negative, though the film had been sitting
    in the
    camera a year or so. This time factor was taken from an old
    Manual of
    Photography by Focal Press, but it was not specific to D76,
    just part
    of a table of suggested factors at a given "temperature
    coefficient".
    The Manual refers to temperature coefficient for developing
    agents and
    listed a table of factors for a coefficient of 2.75. Here is
    a part of
    the table:

    Temp: Factor
    15 deg C: 1.66
    17 deg C: 1.35
    20 deg C: 1.00
    22 deg C: 0.82

    I am just getting back into B&W film again, after a long
    hiatus. Any
    comments on an appropriate development time for the next
    roll?

    Some further searching on Google found the following link
    with some
    more details:

    "A characteristic, named the "temperature coefficient," has
    been used
    as the quantitative measure of the change of activity. This
    is defined
    as the ratio of
    the development times required to produce equal density at
    two
    temperatures differing
    by 10°C., which is, of course, a difference of 18°F. The
    values
    obtained range from 1.3 for metol alone, through 1.9 for
    pyro and
    metol-hydroquinone combinations, to 2.5 for glycine."
    from: http://www.questia.com/PM.qst?a=o&d=97634617
    (in referernce to the book: Handbook of Photography by
    Keith Henney,
    Beverly Dudley; Whittlesey House, 1939.)

    Thanks for any comments.

    The temperature coefficient varies with the developer
    and to some degree with the film so there is no absolute
    rule. For some guidance check Kodak film data sheets. Most
    have graphs showing the variation of development time with
    temperature as well as showing development times for various
    temperatures on the charts. If you are not using a Kodak
    film you can still get pretty good estimates from this data.
    I think Ilford has similar information on their film data
    sheets. The variation for D-76 and Ilford ID-11 should be
    very much the same although the packaged developers are not
    quite identical.
     
    Richard Knoppow, Apr 6, 2008
    #3
  4. sometime.photographer

    Guest Guest

    And keep your fingers crossed and hope by chance the chart is right. Many of
    them are just straight-line extrapolations and that is not how all chemistry
    works. Some of their film development specs are flat out guesses, some upon
    a recommendation of a quesitonable source. One of those sources is a
    hairbrained maniac who frequented this place and hasn't developed a roll of
    film for forty years. Pure impressionism.
     
    Guest, Apr 7, 2008
    #4
  5. How about "there is no coefficient"? These are not simple first-order
    functions.
     
    Thor Lancelot Simon, Apr 7, 2008
    #5
  6. How about "there is no coefficient"? These are not simple first-order
    functions.
     
    Thor Lancelot Simon, Apr 7, 2008
    #6
  7. How about "there is no coefficient"? These are not first-order
    functions.
     
    Thor Lancelot Simon, Apr 7, 2008
    #7

  8. Thanks. This chart is similar to the values in the table, but maybe
    using a different temperature coefficient? As you can see, the
    temperature scale is linear while the time scale is logarithmic.
    Perhaps the temperature coefficient is the slope of the line.

    Why didn't I think of looking there? The film I am using has been
    discontinued a few years (stored in the freezer meanwhile). The chart
    for Plus-X only goes down to 65 deg F, though. Maybe Kodak does not
    recommend processing at low temps? Thanks, anyway.

    Plus-X tech sheet:
    http://www.kodak.com/global/en/professional/support/techPubs/f4018/f4018.jhtml
     
    sometime.photographer, Apr 7, 2008
    #8
  9. sometime.photographer

    Peter Guest

    You have mentioned a number of points of uncertainty:
    long hiatus
    old film
    long time since exposure

    You haven't mentioned much about the rest of your technique (e.g., how
    sure are you that you used the correct exposure allowing for old film
    & etc., why not keep the solutions in a warm room, load the film in a
    tank in your dark room and develop the film at a more convenient
    temperature in a warm room, how accurated is your time keeping,
    temperature measurement and how consistently correct are the solutions
    & etc).

    Personally, I've had poor experience with Plus-x in D-76 at cold
    temperatures. I settled on never developing it below 65F. That was
    decades ago and I forget the details. Perhaps I was wrong.

    Even so, you need to prove you can get a correctly exposed roll of
    your old film developed to normal density and contrast. To do this, I
    thing you need to plan on trying more than one roll of test pictures
    (sheet film is an attractive alternative for such experiments, if
    available).
     
    Peter, Apr 7, 2008
    #9
  10. sometime.photographer

    Andrew Price Guest

    It's a starting point, nothing more. Most people who are seriously
    interested in developing their own film take notes and compare the
    results at different temperatures and dilutions.
    But over the short temperature range quoted (+14 to +24) it is a
    starting point, and one recommended by Ilford and other manufacturers
    of black and white film.
    Hmm... supporting data?
    Do you have any convincing supporting evidence of that assertion?
    Being more specific would add credulity to that statement.
    Indeed - but whose?
     
    Andrew Price, Apr 7, 2008
    #10
  11. sometime.photographer

    jjs Guest

    It may be a stopping point. If the full chemistry isn't active at 60F,
    nothing might happen.
    Bullshit. Those are the recommended ranges, bottom and top, not higher and
    not lower than that range.
    I would, but I forgot the guy's name. Spanky or something like Uranium
    Committee. Yep, that's a pseudo he used. Search for 'dougnut boy', his
    lifelong masterpiece done in high school fifty years ago.
    I wrote that I would if I could recall his name, but some things are worth
    forgetting. I don't know how long you have been around, and I don't want to
    bother looking, but you might remember if you ... wait, It is Michael
    something.
    Michael S (spook, spoor, smegma, something)
     
    jjs, Apr 8, 2008
    #11
  12. Close; you're talking about (dare I invoke his name here, lest he come
    back to torment us?) Michael Scarpitti, aka "Uranium Committee" aka
    "Waffle Boy".
     
    David Nebenzahl, Apr 8, 2008
    #12
  13. sometime.photographer

    jjs Guest

    Yeah, that's the name! He's the guy who claims that Agfa Brovira was overly
    contrasty and he could never get a good print. (Its grades were about one
    lower than Kodak, back when they both made graded paper, and Agfa went from
    0 to 6.) He also claimed that the Leica was the best camera in the world,
    and the Fuckamat enlarging lenses were the very best, and that photography
    could not possibly be an art. Didn't he rename his masterpiece to Doughnut
    Boy? Or is that his new moniker?

    Anyway, he claimed to be an authority on B&W film development and his
    recommendation(s) were in Digital Truth. Be suspicious of ANYTHING that says
    it is the truth.

    Anyway, OP, so develop some Tri-X 125 in 60F or colder water and let us know
    how it goes for you. Or don't. I would choose a more active developer for
    cold water, something recommended for such an application. But WTF do I
    know? I just started taking picture and making wet prints FIFTY years ago.

    My next post will be more to the point of the post. Cold development
    solutions (no pun).
     
    jjs, Apr 8, 2008
    #13
  14. sometime.photographer

    jjs Guest

    OK, I don't have the reference book for cold weather processing on-hand. It
    must be in storage. Leitz had good information in one of their earlier
    books. I might find it this weekend.

    In the meantime, an *authoritative source mentions the rule of thumb
    mentioned earlier - quoting from the book, "a general rule of thumb for the
    range of 65 to 95F is that a decrease of 10F increases the development time
    1.5 times." and they mention that the rule of thumb is just that - am
    approximation.

    Note that they do not include temperatures below 65F because lower
    temperature solutions have more profound differences; they are not covered
    by the rule of thumb.

    * source: SPSE Handbook of Photographic Science and Engineering
    1,416 pages
     
    jjs, Apr 8, 2008
    #14
  15. A digital timer is being used, with lap times for each step in the
    processing. A review of the split times shows that draining the old
    tank being used is taking longer than expected, but longer time is not
    the problem here. It is possible that the film being at room
    temperature for over a year was a factor. The latest roll turned out
    with good density. More later.
    Given that the Kodak datasheets do not go below 65 deg F, this might
    well be the case.
    Getting a good roll done was a priority for me, too. A heater in a
    small area took the temperature of the chemicals up to 22 deg C over
    the course of the day and processing on another roll was done at that
    temperature. This time, D76 at 1:1 dilution was used, and the results
    look good.

    There is a certain satisfaction in the process of developing film,
    sight unseen for most of the processing, and finally seeing the
    results turn out well.
     
    sometime.photographer, Apr 8, 2008
    #15

  16. Thanks. This chart is similar to the values in the table,
    but maybe
    using a different temperature coefficient? As you can see,
    the
    temperature scale is linear while the time scale is
    logarithmic.
    Perhaps the temperature coefficient is the slope of the
    line.

    Why didn't I think of looking there? The film I am using
    has been
    discontinued a few years (stored in the freezer meanwhile).
    The chart
    for Plus-X only goes down to 65 deg F, though. Maybe Kodak
    does not
    recommend processing at low temps? Thanks, anyway.

    Plus-X tech sheet:
    http://www.kodak.com/global/en/professional/support/techPubs/f4018/f4018.jhtml

    65F used to be the "standard" temperature up to the
    early 1940's when it was increased to 68F due to better
    emulsion hardening in manuacture. Much below this one
    encounters problems due to hydroquinone loosing activity,
    but that depends on the pH of the developer. Low temperature
    development is possible and Kodak used to have a brochure on
    how to do it.
    The simple chemical rules for the variation of rates of
    reaction due to temperature and concentration do not always
    apply directly to actual photographic processes because they
    are complex. For instance, development and fixing are
    affected by the diffusion rate into the emulsion which is
    partly dependant on temperature but depends on the history
    of the gelatin so its not simple.
    Kodak appears not to recommend using some developers
    below relatively high temperatures, for instance diluted
    T-Max. In some of the older Kodak charts a preferred
    temperature was indicated by printing the temp in bold type.
    This was around 75F for T-Max and some others. Kodak never
    stated the reason for this but, usually, they had good
    reasons.
    I've found that Kodak's data is usually quite accurate
    although they occasionally blunder.
     
    Richard Knoppow, Apr 8, 2008
    #16
  17. Leading back to first-year chemistry ...
    http://en.wikipedia.org/wiki/Arrhenius_equation
    where the rate of a reaction doubles every 10C.

    A variation on the universal equation:

    Something = Something Else * e ^ -(Energy of the thing / k * T)

    Where k is Boltzman's constant and T is temperature
    relative to absolute zero.
     
    Nicholas O. Lindan, Apr 8, 2008
    #17
  18. Unfortunately, there are several reactions going on at once in a typical
    photographic development bath. For example, consider a tank full of D76:
    the primary development agent (the metol) is being exhausted by developing
    the film, and regenerated by stealing electrons from the other developing
    agents. A buffer reaction is keeping the pH of the solution stable, at
    the same time. More complex developers will have sequestering agents
    grabbing up development-inhibiting reaction products and holding them in
    solution, etc. -- and all these reactions have different energies, thus
    proceed at different rates. Get below or above some threshold temperature,
    and the overall reaction won't run as designed, period, and the
    characteristic curve of the resulting negatives will be...different.

    In any event, if you actually fit curves to the time/temperature data for
    common films and developers (at some constant exposure and density) you
    will find that they are, at least, shallow 2nd-order curves -- not linear.
    And that's within a fairly narrow temperature range, all bets are off once
    you get outside there. The film/developer testing page on Paul Butzi's
    site has some nice examples of the data and the curves that fit it, and
    they are *not* straight lines.
     
    Thor Lancelot Simon, Apr 8, 2008
    #18
  19. sometime.photographer

    jjs Guest

    Perhaps for quite similar chemicals separately, but our developers are
    complex mixes.
     
    jjs, Apr 9, 2008
    #19
  20. Hi, JJS. Did you have any recommendations for cold water processing?
    A check of the Manual I have shows no specific cold water
    formulations. However, it did list a tropical developer that can be
    used to 32 deg C, useful for when summer comes.
     
    sometime.photographer, Apr 12, 2008
    #20
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