true B&W roller transport processing

Discussion in 'Darkroom Developing and Printing' started by Eric Palmer, Mar 2, 2005.

  1. Eric  Palmer

    Eric Palmer Guest

    I have a 20 inch Colenta RA4 roller transport processor. I'm interested
    in setting it up to process black and white prints. Can this be done?
    Are there chems out there for this type of work?

    Thanks,

    Eric
     
    Eric Palmer, Mar 2, 2005
    #1
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  2. Eric  Palmer

    John Walton Guest

    I tried this with my Durst Printo -- you can change the cogs to various
    processing speeds -- Ilford had a white-paper on using more concentrated fix
    solutions and shorter processing times.

    My experience was that it "worked", but I thought using trays to be more
    economic. To really get the maximum black out of a print it seems to take 2
    minutes of development time.

    At least with the roller processor you can maintain a constant temperature.
     
    John Walton, Mar 3, 2005
    #2
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  3. I maintain a constant temperature for Black and White prints by allowing
    the overflow from my Zone VI print washer to overflow into my preliminary
    washing sink. From there, it overflows into my processing sink where my 5
    trays are. No extra water required for these constant temperature baths.
     
    Jean-David Beyer, Mar 3, 2005
    #3
  4. There is (was?) a technique called 'stabilization processing'. It used a
    cheap 2 bath processor and delivered a damp print in ~15 seconds. Popular
    with newspapers in the old days. Prints faded in a month or so unless
    washed. Max black was a dark muddy grey. Ditto max white.

    There are 'Rapid RC' papers that have developer incorporated into
    the emulsion and develop in under 30 seconds.

    As usual: Google knows.
     
    Nicholas O. Lindan, Mar 3, 2005
    #4
  5. Eric  Palmer

    Matt Clara Guest

    Let me chime in with my ignorance--what does the difference in temps mean to
    print developing? I carefully control my film development temps, but pretty
    much let the trays fall wherever (usually 65-75 degrees, over the course of
    a year). I'm not having any problems, per se, but I'm a pretty casual dark
    room user at this point.
    Thanks
     
    Matt Clara, Mar 3, 2005
    #5
  6. Eric  Palmer

    Nick Zentena Guest


    How many baths on the processor?

    Agfa Multicontrast I think is intended for machine use. RA-4 is 45 seconds
    for dev and blix. Agfa Multicontrast with RC paper is 60 seconds at normal
    B&W temps. I forget how fast rapid fix is but you could always finish fixing
    in a tray.

    Nick
     
    Nick Zentena, Mar 3, 2005
    #6
  7. The way I print, it matters little what the actual temperature is, though
    my processing temperatures are never less than about 75F. What does matter
    is that the temperature for a given day not change too rapidly, and
    keeping my trays in a sink with the wash water overflow (supplied by a
    temperature regulating valve) has enough thermal mass that the
    temperatures cannot change rapidly.

    The reason it matters little is that I always develop for the same time (2
    minutes for D-72 1+2, 3 minutes for Ansco 113 -amidol), and adjust
    exposure of the print so the maximum black is produced. So the exposure of
    a print is implicitly calibrated for the developer temperature. The
    temperatures for the other baths do not matter much, provided they not get
    too cold, where the fixing might not work fast enough. It happens that all
    my baths are within 1F, but with papers hardened, this is probably of much
    less concern than with old unhardened films (if you can even get those
    anymore).
     
    Jean-David Beyer, Mar 3, 2005
    #7
  8. Actually, they would deteriorate even faster if washed. They needed to be
    fixed and washed to preserve them longer.

    If not fixed and washed, they had to be kept separate from conventional
    prints as the residual fixing agents in the paper would seriously
    contaminate any surface with which they came in contact.
     
    Jean-David Beyer, Mar 3, 2005
    #8
  9. Eric  Palmer

    Eric Palmer Guest

    Three bath tanks. I'm just wondering if I'm over looking something. I
    plan on slowing the dev time to 120 sec and keeping the temp around 21
    Celsius. Does anyone know what the replenisment setting might be like?
    Should the drying time be a concern? Is there a big difference in
    drying times for B&W RC paper and RA4 paper?

    Thanks for the replys,

    Eric
     
    Eric Palmer, Mar 3, 2005
    #9
  10. Eric  Palmer

    Ken Hart Guest

    When I'm printing B&W RC paper, I keep the prints in a water holding bath
    until I'm done. Then I go into the next room, fire up the old Hope Minilab,
    and run the prints thru the wash racks twice. The second time thru, I let
    the prints go on into the dryer rack. There appears to be no real difference
    in drying between B&W and RA4 RC paper.

    As for replenishment, that would depend on your chemistry and machine. For
    my processor, a replenishment cycle hits every 160 square inches of paper. I
    set the metering pumps so that the proper amount of replenisher(s) are
    pumped in at each cycle. (When using the machine just for washing prints,
    replenishment is not an issue; only water flow rate.)

    My question to the OP would be do you process sufficient B&W to provide a
    tank turnover before the chemistry goes sour? If, for example (these figures
    are pulled from thin air!), the replenishment is 10mL per 8x10 and the
    developer tamk holds 10L, than 1000 8x10's will have to processed for a tank
    turnover. If the tank (working) developer has a life of 4 weeks, you need to
    process an average of 250 8x10's a week. This assumes that you don't dump
    the chemicals after use.

    Ken Hart
     
    Ken Hart, Mar 3, 2005
    #10
  11. Eric  Palmer

    jjs Guest

    I agree. Print developing is pretty much a completion process. 2 1/2 minutes
    of Dektol 1:2 does the trick. Several seconds on either side is for the
    annals to worry about.
     
    jjs, Mar 4, 2005
    #11
  12. Eric  Palmer

    darkroommike Guest

    I did this for years where I worked using an old Pako film processor,
    Developer was Kodak PolyMax RT (I think--made for the Kodak Roller
    Transport) and fix was Kodak Rapid fix at Dilution for film but without
    hardener so that it would wash out faster, paper was Ilford Multigrade RC
    (III I think on 3.5" and 5" rolls) and I taped scrap film to the beginnings
    of the rolls to use as leaders since this machine would not process paper
    with out a guide card. I would suggest you stay away from developers like
    Dektol that leave a lot of crud buildup in trays.
     
    darkroommike, Mar 4, 2005
    #12
  13. Eric  Palmer

    Bernie Guest

    Eric, this is so easy to do, but most people don't bother trying. You can
    run any B&W RC paper in this processor without making any changes to the
    RA-4 specs. 45 seconds at 35C is fine for most B&W papers, maybe a little
    longer than needed for the developer incorporated papers, but fine.

    Use chemicals designed for replenished processing systems, such as Kodak
    Polymax RT Developer Replenisher, and either Polymax RT Fixer, or Rapid
    Fixer mixed 1:3 with no Part B (hardener). Using tray developers like
    Dektol, Polymax T, or D-72 will allow too much silver and dirt to build up
    on the rollers. Machine developers like Polymax RT have additives which help
    maintain a clean processor.

    Replenishment rates of about 20 mL/ft2 for developer and 30 mL/ft2 for fixer
    will work well.

    Good luck and enjoy the easier work in the darkroom.
     
    Bernie, Mar 12, 2005
    #13
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