Problems with print to print consistensy

Discussion in 'Darkroom Developing and Printing' started by Michael Sig Birkmose, May 31, 2006.

  1. Hi,

    I have recently had som problems with some portraits I was doing in black
    and white. Basicly what I'm trying to achieve is to make multiple copies
    (3-4) of the same print.

    Basicly what I'm doing is:

    Exposing the paper for 30 seconds, hold back face for 5 seconds, and then
    burn in the corners for another 35 seconds.

    The paper I'm using is FB paper (forte polywarmtone), which I develop for
    4 minutes. After stop bath, fixer, hypo eliminator, I tone in selenium for
    5 minutes.

    After making test strips etc, I made my first print where all
    values where just perfect. Then I needed to make a 4 copies of this print. I processed these in exactly the same
    way, but the got to bright - this results in the face on the portrait
    looking to pale.

    I have access to a meter to measure the light output from the enlarger and
    this seems pretty constant. Over a period of 3 minutes the output
    fluxtuactes maybe maximum 3 percent (it goes up and down, so maybe in
    average its less than 3 percent).

    So this has led me to believe that my problem is not the enlarger. It
    should also be noted that before I expose any print, I let the enlarger
    warm up for a minute or so, to make sure that output levels are similar.

    Also, since my development time is quite long - 4 minutes, I don't think
    that its variation in development times.

    What I think could be the problem is the temperature of the developer /
    the selenium toner, or variations in agitation. It has been a bit chily
    here in Denmark recently, so perhaps it could be a temperature problem?

    Between exposing the first perfect print, i developed the print, stop
    bath, fixer, hypo clear, toner, dried the print with hair dryer. This
    process takes maybe 20 minutes. I guess in 20 minutes the temperature ca n
    vary enough? I'm considering byuing a dishwamer to put under my trays to
    make sure that temperatures are kept constant.

    So basicly my question is if my theory seems feasible - that I'm having a
    temperature problem. Or is there something else that I may be missing? The
    papers used where all from the same batch (the same box of papers), so I
    don't think this could be the problem either.
    Michael Sig Birkmose, May 31, 2006
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  2. Michael Sig Birkmose a écrit :
    Expose several small sheets of paper (from the same box) on a contrasty
    grade without negative to obtain a mid-grey.
    Develop them together, then you'll know if these variations come from
    the exposure or the development.

    Several years ago, I was doing tests in a similar manner and was unable
    to obtain a constant exposure. I then stabilized the enlarger voltage
    (it's a halogen light source) and prints are now much more consistent.

    Claudio Bonavolta
    Claudio Bonavolta, May 31, 2006
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  3. More questions:

    o Are the three 'too pale' copies identical?
    o How much lighter are the faces - 1 zone, 1/2 zone, 1/4 ...?

    When I have had problems like this the cause is the most common
    source of error in the darkroom ... me.
    Nicholas O. Lindan, Jun 1, 2006
  4. o Are the three 'too pale' copies identical?

    They are quite similar - maybe increasingly paler.
    I would estimate around 1/4-1/2 zones.

    I have played with this print in two sessions, and the reason for comming
    back was that the "Copy" prints got to pale in the first session. Then I
    returned in another session, and got a perfect work print. Again my first
    "copy" print got to pale, and then I gave up and went home :)

    My enlarger is the devere 504, so I assume that the transtab power supply
    takes care of voltage stabilization? It looks stable when I measure the
    light over a period of 3 minutes - the light output hardly fluctuates.

    Does it seem feasible that a temperature drop in both developer + toner
    around 0.3-0.5 degrees could cause the problems?

    If this is the case, would a dishwarmer for the trays ensure that the
    temperature would be kept failry consistent, or are these not precise

    Best regards,
    Michael Sig Birkmose, Jun 1, 2006
  5. Michael Sig Birkmose

    Mike King Guest

    You said that you developing time is 4 minutes, I wouldn't think that 0.5
    degree C. would have that much effect. I would probably just extend
    development another 30 seconds to compensate. Tray warmers are not that
    accurate but you could put the developer tray into a larger tray of water at
    20 deg. C. (or whatever your ideal temperature is).

    Another thought, what size prints are you making and how much developer in
    your tray?
    Mike King, Jun 1, 2006
  6. Michael Sig Birkmose

    Pat Guest

    I haven't been in a wet darkroom for years, but think it's wonderful
    that people are still doing wet photography. (BTW, I think it is a
    MUCH better way to learn photography than digital).

    Anyway, a few thoughts/questions. How much time elapsed between your
    sessions. Were they same day or quite a bit of time apart?

    Have you checked your timer for consistancy? I once had a timer go
    bad. If you set the clock, it gave one time but when you hit the
    botton to repeat the exposure, it gave a different time.

    For the pale pix, have you duplicated it and left it in the developer a
    longer time and see if it brings out more of the image?

    Sorry for intruding on your group. I usually just read it.

    Keep up the good work.
    Pat, Jun 1, 2006
  7. Michael Sig Birkmose

    Lloyd Erlick Guest

    June 1, 2006, from Lloyd Erlick,

    It's easy to test this thought before going
    out to spend money.

    Place your developer tray in a larger tray of
    warm water. Keep a thermometer in the
    developer, and get used to how much (hot)
    water to add to the water jacket to get the
    developer to the desired temperature for each
    print. In other words, each time you are
    ready to make a new print, adjust the
    developer temperature specifically.

    This method takes a bit of time, but not
    much. It also requires a thermometer you
    trust, but you should have one anyway.

    If you find this is the correct solution,
    investing in a tray warmer might be

    I work single-tray, so keeping solutions at a
    desired temperature is quite easy. I never
    bothered with electric warmers, I used a warm
    water bath for years (well, winters). My
    darkroom is no longer in a cold basement, but
    I still keep my jug of selenium toner in a
    hot water bath (I like to use selenium at
    around human body temperature...).

    Consistency is one of the most important
    things in a darkroom, and quite difficult to
    achieve sometimes. Longer enlarger exposures
    are easier to control, and errors and
    variations become a smaller percentage of the
    overall exposure. Maybe you should stop down
    the enlarger lens one stop...

    Good luck. I'm sure many of the darkroom
    detectives around here will be delighted to
    work on this problem with you!

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jun 1, 2006
  8. Michael Sig Birkmose

    Lloyd Erlick Guest

    June 1, 2006, from Lloyd Erlick,

    no -- it's ME!
    Lloyd Erlick, Jun 1, 2006
  9. Michael Sig Birkmose

    Lloyd Erlick Guest

    June 1, 2006, from Lloyd Erlick,

    This seems very unlikely to me. Half-degree
    fluctuation would not be terribly significant
    in black and white print making. I doubt a
    dish-warmer would give better control.

    How old is the lamp in your enlarger? How
    close to a natural death is it? Would it cost
    you a lot to put in a new one? This doesn't
    seem too likely a cause to me, though.

    Lloyd Erlick Portraits, Toronto.
    telephone: 416-686-0326
    Lloyd Erlick, Jun 1, 2006
  10. Michael Sig Birkmose

    dan.c.quinn Guest

    Latent image decay does not seem likely. A recent thread
    on Apug mentioned that as little as 10 minutes twixt exposure
    and development can make a difference.
    The much more noticeable change is twixt your Perfect and
    the First Copy. Correct? Dan
    dan.c.quinn, Jun 1, 2006
  11. Latent image decay does not seem likely. A recent thread
    Hi dan,

    It sounds like you think that I exposed all the copies and once and then
    developed them one after another. This was not the case.

    I exposed and immediatly developed the perfect one, processeded it, dried
    it with an airblower etc. Then I exposed and developed the next one.

    I will be going to the darkroom again today, to conduct some tests, so I
    will follow up with my findings :)
    Michael Sig Birkmose, Jun 2, 2006
  12. Michael Sig Birkmose

    Art Reitsch Guest

    Well, here's another thought to eliminate the passage of time as the
    culprit. Expose several sheets one after the other in exactly the same
    ways and store them in a light tight place. Then develop them one after
    another, or two or more at a time in the tray. Now you've eliminated
    everything but possible variations in the paper sheets themselves.
    Art Reitsch, Jun 3, 2006
  13. Well, no. Aging and exhaustion of the chemicals, unless you process the
    sheets one-shot. Process them in order of exposure perhaps.
    Jean-David Beyer, Jun 4, 2006
  14. Michael Sig Birkmose

    YD Guest

    I can't recall if you stated the size of the prints and the quantity
    of developer. If you used too little it may have become just enough
    exhausted by the first print to affect the others.

    - YD.
    YD, Jun 7, 2006
  15. I can't recall if you stated the size of the prints and the quantity
    I'm developing 12x9.5 " prints. 1 L of chemicals.
    Could that be to little?
    Michael Sig Birkmose, Jun 7, 2006
  16. Michael Sig Birkmose

    YD Guest

    At that size you should be able to do several without noticeable
    exhaustion. I just wondered since you stated that each subsequent
    print is a bit paler than the previous. If the effect is repeatable
    you should be able to compensate for it. Can't really say, as I
    usually don't do many prints in a row I end up throwing the developer
    due to oxidation long before it's really spent.

    Just grabbed the calculator. At 24 x 30 cm, 1000 ml will cover it by
    about 1.4 cm height, not counting that the tray is slightly larger.
    Unless it's heavily diluted it should be more than enough.

    The manufacturer usually has some data-sheet on-site stating the
    maximum total area that can be developed with a single batch.

    - YD.
    YD, Jun 8, 2006
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