Film not fully developing in Jobo 1520 Unitank.

Discussion in 'Darkroom Equipment' started by Let's Take Your Car, Aug 29, 2011.

  1. Let's Take Your Car

    Let's Take Your Car Subscriber

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    I purchased the Rollei Compard Digibase C41 chemistry to test out in my Jobo CPE-2 with a 1520 Unitank (takes one 120 reel). I would normally use a 1540 tank and knock out two reels, but the set of chemistry I bought was the smallest batch and made only 250 ml of chemicals per step. Thus, I was relegated to the smaller 1520 tank.

    After developing at the proper times at 37.5 deg C I had two rolls of film turn out with only 4 images developed, and the other 8 on the roll completely blank. I'm not talking just faded, uneven development or striping, I mean seemingly untouched by developer. The 4 shots that did develop properly came out great, no irregularities.

    Both times I ran the developer, the 4 shots that did come out were on the outermost track of the reel (AKA the section of the film you can see when you first remove the reel from the tank after developing). The rest of the film that cannot be seen in the inner tracks was totally undeveloped both times. Check the pictures I attached for one of 120 rolls, the other roll looks identical.

    I am confident the issue is mechanical/physical with the tank, not an issue with the developer. I filled the tank to the correct capacity (it is listed for 240 ml and I used 250 ml on each step), so I don't believe it is a lack of chemicals. Also, the reel was only loaded with one 120 strip each time, so the film should have been easily submerged being as it was on the outermost portion of the reel.

    So then:

    Is the outer section of film blocking chemicals from getting only the rest of the film surface perhaps? Is there an issue with the 1520 tank that I am unaware of? I truly don't know what could be causing this, it is a mystery.

    Other details: 1520 tank was used with a cog and lift. Also, both reels were loaded smoothly, they film was not off track or touching itself.

    Thanks for your mystery-solving skills,

    David
     

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  2. michaelbsc

    michaelbsc Member

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    OK, pardon me for asking an obvious question, but are the frame numbers on the film rebate edge showing properly throughout the length of the film? I cannot see them adequately in the pictures.
     
  3. Let's Take Your Car

    Let's Take Your Car Subscriber

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    Yes they are. The successfully developed images are shots 1-4, the blank images are for 5-12.

    Which, now that I consider it, means the film must have developed, and I have an issue further up the line, perhaps with my camera (yeesh_.

    Thank you for considering that very important detail.
     
  4. pentaxuser

    pentaxuser Subscriber

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    I will risk appearing to be curmudgeonly here but there is definitely a case for an article on comprehensive diagnosis on film development problems.

    It would assist so many and prevent a "jumping to conclusions" syndrome that afflicts users who are understandably disappointed when things go wrong but whose disappointment tends to lead to the " I got a rope, so what are we waiting for reaction" that I used to love in the 1950/60s westerns.

    How many "innocents" did the various brave sheriffs and "Sugarfoot" used to save by rationale and painstaking analysis?

    By the way, whatever happened to "Sugarfoot" - the actor who played the part, I mean?

    pentaxuser
     
  5. ic-racer

    ic-racer Member

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    You are correct, it is not a problem with the amount of developer. What kind of camera? How was it loaded? Has it worked correctly before? Is it a Kiev?
     
  6. Sirius Glass

    Sirius Glass Subscriber

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    [An aside comment: I get more exercise when I am "jumping to conclusions"!]

    I agree that is sounds like a camera problem which was my first thought, but I did not comment until I saw more information.
     
  7. Let's Take Your Car

    Let's Take Your Car Subscriber

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    Apologies for this thread shifting to the discussion of a camera problem, not darkroom issues.

    And to pentaxuser, thank you for letting me know about that, I am new around here.

    The camera is a Hasselblad 500C/M with a late model A12 back. I've developed hundreds of rolls out of this back, so I don't know what could have changed with it. The camera advanced through the first 4 shots, why the camera would decide to stop shooting after that is dumfounding. I'm investigating the film back I guess.
     
  8. michaelbsc

    michaelbsc Member

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    Hey come on now. My Pentacon 6 TL is perfectly capable of doing this too.

    And you can leave the lens cover on any number of range finders. (Of course *I've* never made that mistake personally.)
     
  9. MattKing

    MattKing Subscriber

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    Were the "missing" photos shot with flash?