Whoops Developing times...

Discussion in 'B&W: Film, Paper, Chemistry' started by mr. mohaupt, Apr 20, 2009.

  1. mr. mohaupt

    mr. mohaupt Member

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    Ok guys what are your thoughts on this.

    I have a bulk roll of what I thought was Tri-X400. I picked up some Rodinal and decided to give it a whirl. Well seeing as how I am on the road 4 days a week I just decided to bring it with me and scan the negs when I get back home but I realized I made a mistake. The film was really Agfa APC 400!!!


    I use Digital truth for my times and mixed up my developer at 1 + 60 and for Tri-x it was 15 mins

    So after I found out what the film really was I checked out the times for Agfa APX 400 and they listed 1 + 50 320-500 11 mins.

    So since my mix was a bit more diluted you think the time was close? The photos are of nothing really in particular I just wanted to see what the results of Rodinal were really like. Just eye-balling the negatives they look a "little" dense but until I shoot another roll and develop it at the right times I wont know.


    Thanks in advance!
    ~m
     
  2. Christopher Walrath

    Christopher Walrath Member

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    Well, let's see. 15 minutes is about a 40% increase in developing time. Your dilution was 1.7% as opposed to 2%. I think you're gonna have a little more contrast and density than you intended but at that dilution it shouldn't be TOO far off.
     
  3. mr. mohaupt

    mr. mohaupt Member

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    Digital Truth doesn't give times for 1 + 60 or 1 + 70, how could I determine the developing times for those dilutions?

    Thanks!
    ~m
     
  4. DarkroomExperimente

    DarkroomExperimente Member

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    not as bad as my first use of HC110:

    I made the classic dilution error and used it at 1:7 instead of 1:31

    ouch...horrible
     
  5. mr. mohaupt

    mr. mohaupt Member

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    Does anyone have an equation or a table to determine developing times for dilutions smaller then 1+25 or 1+50? I want to get *finer* grain results then 1+25
    I am guessing there has got to be some constant where (x) time = (y) dilution?

    Thanks!
    ~m
     
  6. srs5694

    srs5694 Member

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    If you're after finer grain you should switch away from Rodinal. If you need a liquid concentrate, then perhaps HC-110 would be a better choice. (I've never used HC-110 myself, though.) If a powdered developer is OK, then D-76 or XTOL are good general-purpose developers. There are others that produce still finer grain, but usually at the cost of film speed and/or acutance.
     
  7. DarkroomExperimente

    DarkroomExperimente Member

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    can you plot the data you have on graph paper or something and see if it's a straight line & then extrapolate?

    I'm sure there's a "reciprocity failure" for extreme dilutions
     
  8. mr. mohaupt

    mr. mohaupt Member

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    You know I will try that right now, see what I can get....


    As for Rodinal I guess I am not looking for FINER grain per say but finer then what 1+25 gives you. I like the liquid concentrate because it is easier to mix up on the road for me.

    ~m
     
  9. mr. mohaupt

    mr. mohaupt Member

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    I am not sure how accurate this is. I just plotted a line graph on my computer.

    I got y=a*x+b, a=-.6667, b=8.6667

    Where y is the % of the mixture and x is the time. The points I used as my known points were (1+50)@500ml= 2% @10 mins and (1+25)=4% @11 mins

    For (1+60) 1.7% the graph is telling me ~10.46 mins which is telling me my negatives should have came back black??


    Thoughts?
    ~m
     

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