Arbitrary temperature for paper processing

Discussion in 'Darkroom Developing and Printing' started by Steven Woody, Jun 6, 2006.

  1. Steven Woody

    Steven Woody Guest

    hi,

    i am think if it is legal to use arbitrary processing ( solutions )
    temperatures for paper processing. the basic idea is that i want to
    adjust exposure time to compensate differences between actual
    processing temperature and standard 68F.

    here is 85F all night. to keep solutions in 68F for at least 20 mins
    consistantly is too hard to do. if above method is ok, i think i can
    stick to 85F and by doing a test trip to determind the corresponding
    minimun-print-time.

    any comments from are highly appreciated.

    -
    woody
     
    Steven Woody, Jun 6, 2006
    #1
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  2. Steven Woody

    Mike Guest

    (Excuse the spelling PC spell checker is not yet reinstalled.)

    Couple of issues to consider regarding paper processing at elevated temps:
    1. Extremely short processing times, might be alleviated by higher than
    normal developer dilutions. Standard MQ developers (less sure about other
    types) get their performance by super additivity of Metol and hydroQuinone,
    developers may not perform as expected when used outside the temperature
    range recommended by the maker, I am not an expert on tropical developers (I
    live in Iowa where the summer only FEELS tropical) so I am not sure there
    are any currently available packaged tropical paper developers, not sure
    there ever were, a quick search on GOOGLE turned several tropical film
    developers but no joy with paper developers.
    2. Some paper emulsions may be non-hardened, you may need to use a
    hardening fixer, emulsion could be pretty soft and easily damaged by tongs
    in the developer.
    3. Wash times should also be shorter but it's a good idea to test any
    assumtions made about how much you can shorten wash times.

    Good luck,
    darkroommike
     
    Mike, Jun 6, 2006
    #2
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  3. The temperature affects the speed of development. This is
    much less important for paper than film since paper is
    generally developed to its maximum density while film is
    developed to a given contrast index. My main concerns would
    be the effect on the emulsion. Probably any modern RC paper
    is hardened enough to withstand 100F processing but some
    fiber papers may not be and some European papers may not be.
    One way to deal with this is to add some Sodium Sulfate (not
    sulfite) to the developer. This serves two purposes: it
    slows down the development a bit, and, it acts to reduce the
    swelling of the emulsion. For D-76/Dektol Kodak recommends
    adding 100 grams per liter of working solution diluted 1:2.
    A non-swelling stop bath can be made by adding about 45
    grams per liter of Sulfate to standard stop bath. Hardening
    fixing baths don't need anything because the hardener
    prevents swelling (that's what its for). The above amounts
    are for Sodium Sulfite, dessicated. According to Kodak the
    development times with the Sulfate and at 85F to 90F will be
    about the same as for the standard developer at 68F.
    I would test to see if you really need to do this.

    68F was adopted as the standard temperature in about 1940
    because that's what the emulsions of the time could take
    without problems from excessive swelling. Before that the
    standard temp was 65F.
     
    Richard Knoppow, Jun 6, 2006
    #3
  4. Steven Woody

    Steven Woody Guest

    i am using ILFORD RC paper, is it hardened enough to be processed high
    temp without harmful swelling ?
    thanks. i am so interested in the Sulfate solution. is there any
    articles/papers on net which described the details information about 1)
    how to mix the solutions using Sulfate ( should i add the Sulfate in
    any order with other chemistries ? ) 2) the development time
    recommended.
     
    Steven Woody, Jun 6, 2006
    #4
  5. Steven Woody

    Mike Guest

    Ilford makes (or at least made, past tense) a rapid access roller transport
    paper processor that would work with Multigrade, faster throughput by high
    temp processing. Most, if not all, RC papers will process just fine at
    higher temps--up to 100 degrees, it's only FB papers and certain "old style"
    products you need to be a bit more careful.

    Mike

     
    Mike, Jun 6, 2006
    #5
  6. Steven Woody

    Steven Woody Guest

    okay, thank you :) and i still also like to know the precisely
    process and chemistry mixing order of the Sulfate method. hope someone
    could tell me.
     
    Steven Woody, Jun 6, 2006
    #6
  7. Steven Woody

    dan.c.quinn Guest

    I think the sulfate method dates from 60 and more
    years ago when emulsions were unhardened and needed
    lower processing temperatures. I'd dare to say that any of
    today's papers can take 82 degrees. Be carefull though.
    To counter the developers hyper activity at that
    elevated temperature I would lower it's ph. Just about all
    print developers are made active by use of sodium carbonate
    which has a high ph; is very alkaline. Add sodium bicarbonate
    in varying amounts to a few small volume working strengh
    solutions. Then test for development times.
    The bicarbonate will lower the ph and so lower the stress
    on the emulsion. Also, activity will be reduced and so developing
    time increased. A few grams of it may go a lot farther than
    the same amount of sulfate. Dan
     
    dan.c.quinn, Jun 7, 2006
    #7
  8. Some snipping here....

    Most RC papers will take high temperatures without
    trouble. Try a scrap in water and see if there is any
    problem.
    I made an error about the amount of Sulfate for working
    solution D-72/Dektol, its 150 grams per liter, not 100 as
    stated above. This applies for most standard print
    developers.
    The Sulfate produces what is called a salt effect which
    tends to reduce the swelling of the emulsion. Salts include
    sulfate, sulfite, carbonate, etc. Developers with not to
    high pH and those with a lot of sulfite in them, like D-76,
    are relatively low swelling. Print developers tend to have
    much higher pH and less salts so they produce more swelling.
    Many modern films and papers have emulsions which are
    only partially made of gelatin. Modern emulsion making
    includes polyesters of various sorts, essentially plastics.
    These emulsions are much harder than the traditional ones.
    Also, there are hardening agents used in making the emulsion
    which are much more effective than those in the past, so
    excessive swelling and reticulation (wrinkling from
    softening) of emulsions is relatively rare now.
    You probably do not need to add Sulfate. It can be used
    to increase development time if you find it too short at 85F
    but I don't think this will be a problem.
    Ilford papers are "modern" in the sense that they are
    well hardened and will withstand high temperature
    processing.
    This same hardness applies to toning. Many toning
    formulas recommend the use of an auxilliary hardener either
    before or after toning to avoid emulsion damage. This extra
    hardening step is rarely necessary with current paper.
    I have high temperature water problems in Los Angeles
    during summer so I know what you are talking abuot. At the
    moment the tap water is around 73F but it can get above 80F.
     
    Richard Knoppow, Jun 7, 2006
    #8
  9. Steven Woody

    Steven Woody Guest

    thanks !
    hi, Richard, would you like to share me some tips in high temp ?
     
    Steven Woody, Jun 7, 2006
    #9
  10. Woody,

    I used to live in the tropics and faced the same problem. I solved it
    by using a divided developer. This is very easy to do if you mix your
    own developer. Simply separate out the alkaline activator (sodium
    carbonate) from the other ingredients. Put the developing agents into
    one tray--call it Bath A-- and the sodium carbonate in a second
    tray--Bath B. The amount of the sodium carbonate is not critical--about
    half a cup full per 2 liters of water.

    After exposing your paper, put it into Bath A for 15-20 seconds. Again,
    time is not critical. You can leave it in there all day, if you like,
    and you will not see any image appear in Bath A. The latent image is
    simply soaking up as much of the developing agents as it needs to
    develop to completion. Then, with no rinse in between, move it to Bath
    B, and in about 30-45 seconds, it will develop to completion. It cannot
    overdevelop. Only the amount of developing agent soaked up by the image
    in Bath A will develop in Bath B. Once completed development stops.

    By dividing your developer in this way, you gain several advantages:
    1. You eliminate the need for time/temperature controls. Any
    temperature from 50F-100F will work just fine.
    2. You can't overdevelop or build up additional contrast by leaving it
    in longer than necessary.
    3. Chemicals in Bath A will not become exhausted, simply used up in
    volume over time. They can be re-used again and again for months before
    the solution will eventually spoil through oxidation. The carbonate in
    Bath B does become exhausted after use--I can get about 30-40 8X10's
    from a tray. But since carbonate is so cheap and readily available,
    it's a matter of mere pennies. Just throw it out after each session.
     
    LR Kalajainen, Jun 7, 2006
    #10
  11. Steven Woody

    Steven Woody Guest

    thank you! i've heard the method and found it's very useful, only one
    question left in my mind: why not everybody use this technique?

    and, dear Kalajainen, would you please tell me how much sodium
    carbonate ( in grams ) i need to make a 1L bath B? here i don't get a
    standard cup :)

    thanks again!

    -
    woody
     
    Steven Woody, Jun 7, 2006
    #11
  12. Steven Woody

    dan.c.quinn Guest

    Certainly why not more? I've an excuse. I process
    using only a single tray and one-shot chemistry. If I had
    several or more prints to process through the same chemistry
    and they were no larger than about 8x10 then I could/would
    multi-tray process.
    As it is, with my compact darkroom, I can single tray handle
    just about any size print one's heart could desire. I may give the
    A then B method a single tray try although I think good
    chemistry may go down the drain. Dan
    I'd start with 2 grams in 1/4 liter. That would be good
    for one 8 x 10. Dan
     
    dan.c.quinn, Jun 9, 2006
    #12
  13. It really is not very important to have a precise amount. If you have
    less, the Bath will exhaust more quickly; if you have more, it will last
    longer. About 30 grams should be fine.
     
    LR Kalajainen, Jun 9, 2006
    #13
  14. It appears that modern VC papers do not need stringent time/temp
    controls and do not continue to develop past a certain point, thus
    taking away some of the benefits of divided developer. However, where
    ambient water temperatures are high (in Malaysia where I lived, the
    ambient water temp in my air-conditioned darkroom was about 85F) it is
    still a godsend to eliminate time/temp variables. I used to develop my
    film this way too in order to avoid grain the size of basketballs from
    the warm water. The film developer was just D-76 divided with the borax
    separated out into Bath B. Time was a factor with film--it takes longer
    for the process to come to completion, so I usually found I had to give
    the film about 3 minutes in each bath.

    Although this won't help you in your small darkroom, Dan, the other good
    thing about divided developer for printing with graded papers is that
    you can make up two different Bath A's-- one a low contrast formula such
    as Ansco 120 or Kodak Selectol and one a normal formula such as D-72 or
    Ansco 125. Say I have a neg that needs a #1 1/2 grade, but I only have
    a grade #2 paper. By running it through the soft Bath A and then
    through Bath B, I could get a true 1 1/2 grade contrast. But you do
    have to have enough sink space for the extra trays.
     
    LR Kalajainen, Jun 9, 2006
    #14
  15. In my last three darkrooms, I've been fortunate enough to have enough
    length (although my present darkroom is the narrowest I've had) to have
    at least an 8-foot plywood/fiberglass homebuilt sink. So tray space has
    not been a problem. I've never done the 2 fixer stuff. Maybe in a
    hundred years my prints will fade prematurely, but I won't care about
    it. Meanwhile, the jury is still out on whether 2 fixer baths are
    really more archival than one. With only a water stop bath and no
    hardener in my fixer, I'm betting that my prints will last as long as I
    or most people could want. I don't let my fixer become exhausted by
    running too many prints through it. And I use fixer remover before
    final washings, so my 35 year-old prints (even some RC's) that still
    look as good as when I made them will probably keep going awhile longer.
    What dilution do you do for your very dilute one-shot fixer?

    Larry
     
    LR Kalajainen, Jun 10, 2006
    #15
  16. Steven Woody

    Lloyd Erlick Guest


    June 10, 2006, from Lloyd Erlick,

    Actually, this is just the sort of situation
    where the single-tray approach is at its most
    useful. Instead of multiple trays, only some
    sort of appropriate containers would be
    needed for the various developers. My
    favorite containers held cat food originally;
    my cat had to eat some of it, but several
    jugs came from the good ol' dumpster.

    These several developers could be kept at
    different temperatures, too, if desired. Just
    put a water bath under each jug. And a
    thermometer inside...

    The single tray approach frees up a lot of
    space so one can experiment with a variety of
    methods.

    regards,
    --le
    ________________________________
    Lloyd Erlick Portraits, Toronto.
    website: www.heylloyd.com
    telephone: 416-686-0326
    email:
    ________________________________
    --
     
    Lloyd Erlick, Jun 10, 2006
    #16
  17. Steven Woody

    Lloyd Erlick Guest

    On 9 Jun 2006 16:13:02 -0700,

    June 10, 2006, from Lloyd Erlick,

    I wonder if people who have never worked
    single tray might worry that the print would
    fall out when the tray is upended to drain? I
    thought that might be a problem before I
    tried it; I've shown people how I work and
    first time they all worried it would fall
    out.

    In fact, the wet print sticks to the wet tray
    and could not be shaken or dumped out if your
    life depended on it.

    regards,
    --le
    ________________________________
    Lloyd Erlick Portraits, Toronto.
    website: www.heylloyd.com
    telephone: 416-686-0326
    email:
    ________________________________
    --
     
    Lloyd Erlick, Jun 10, 2006
    #17
  18. Steven Woody

    dan.c.quinn Guest

    Your're missing the point of the two-bath fix. The point is the
    increased capacity; much more capacity with a two-bath fix. While
    the first bath loads up with silver the second bath maintains very low
    silver levels. For our purposes that defines an archival fix; very low
    silver levels. Although Ilford no longer mentions the word archival
    they, in their PDFs, do imply a maximum level of 0.5 grams
    PER LITER. That level is independent of brand, dilution,
    type, sodium or ammonium, one or two bath.
    That's where my VDAF, Very Dilute Archival Fix, comes in. Just
    enough chemistry to thoroughly fix with a large volume of solution.
    If interested in giving it a whirl use 10ml of your concentrate and
    water to make 250ml of fixer; 1:24. Good for one 8 x 10. Allow
    three minutes with agitation as I've described on the current
    tray size thread.
    That 10ml should do it. Papers and concentrates do vary
    some little. I'm running around 8ml using P. Formulary's A Thio
    unadulterated. At 10ml per 8 x 10, 100 per liter, how does
    that compare with your current usage? Dan
     
    dan.c.quinn, Jun 11, 2006
    #18
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