Negatives "Curve"

Discussion in 'Digital Photography' started by ppc_michael, Jan 30, 2009.

  1. ppc_michael Guest

    ppc_michael

    Joined:
    Apr 26, 2005
    Location:
    Los Angeles, CA
    #1
    I just developed my first roll of 35mm and the pictures turned out really nice! I thought for sure I would eff it up somehow.

    Anyway I have a question: my negatives sort of curl or develop a curve. Not curling back up like how it is wound in the film cartridge (I used weighted film clips to make sure it dries straight that way), but the other way, like how measuring tape looks, so it's straight but not flat.

    Is that a known issue with a known fix? Maybe I used the fixer for too long or something?
     
  2. GotMyOrangeCrus macrumors regular

    #2
    Congrats, there is nothing like developing your first roll of film and its nice to see people still shooting film. Film rules!!

    This is actually very common especially if you over wash or use a heater in the drying process. Some films are worse than others. Stick them in pages and store them in books and they will flatten out over time. Its really not an issue since your neg holder flattens the neg while printing. Again store them in pages and in books and as the months go by you will notice them flattening out.
     
  3. ppc_michael thread starter Guest

    ppc_michael

    Joined:
    Apr 26, 2005
    Location:
    Los Angeles, CA
    #3
    Thanks very much! I did put them in archival pages so I will wait for them to flatten that way.

    I'd still like to track this down though. I'm using Tmax 400. I did a "pre-wash" for about a minute before developing, and washed it again at the end, of course. I used Photoflo in the wash at the end, do you think that would have anything to do with it?

    To dry I just hung it up in my bathroom (with the film clips), so no heater or anything like that.
     
  4. aquajet macrumors 68020

    Joined:
    Feb 12, 2005
    Location:
    VA
    #4
    Yes, a very common problem which can be especially pronounced now that we're in the winter months, when the colder air has less moisture-holding capacity. The trouble is that the emulsion side of the film tends to contract when the humidity is low, causing the film to curl edge-to-edge. One thing you could try is hanging the film to dry in your bathroom after a hot shower. Once dry, place the negatives in sleeves and place them under a heavy book. This should minimize the amount of curl, but don't be surprised if it never quite goes away.
     
  5. GotMyOrangeCrus macrumors regular

    #5
    No, photo-flo has nothing to do with it. A small amount of curl is actually normal. Just remember to use a weighted film clip on the bottom. If the excessive curling continues try adding a bit of humidity to the area your drying the negatives in, either by a humidifier or other means at your disposal. The problem lies in the fact that the emulsion shrinks a bit when drying yet the film base does not. Again a small amount of curl is normal.

    Dont let it get to ya and dont think your doing something wrong. I still get rolls that have excessive curling and I have been doing film for over 15 years. Remember store them in sleeves, store the sleeves in binders and stack the binders so they are always being flattened. They will flatten over time. Some of my old film that has been stored like that for years is as flat as a pancake now with absolutely zero curl.
     
  6. leighonigar macrumors 6502a

    Joined:
    May 5, 2007
    #6
    Interested that people are recommending making the room more humid. Surely that's just delaying the curling? Or are you trying to avoid a sort of helix?

    Oh the original issue, all (five) of the rolls of film I've developed have done this to some extent.
     
  7. GotMyOrangeCrus macrumors regular

    #7
    No it doesn't just delay the curling. You see the film can have a certain amount of moisture trapped in the emulsion without still being in need of drying. In other words it feels dry, appears dry, and you can even store them in sleeves yet the film still has some moisture in it.

    Think of your film as a sponge. That emulsion layer absorbs liquid and then when dried shrinks down a bit. Now for arguments sake lets imagine that you only need to suck 95% of the moisture out of your film before its safely considered dry and ready to be cut and stored in sleeves. Now you shoot a roll, develop it and hang your film to dry in a room with very little humidity. You wind up sucking more than 95% of the moisture out and at the same time your getting excessive curling. By adding a bit of moisture to the air you are now capable of drying to that 95% figure and by keeping a bit of moisture in the neg you retard any additional curl.

    I am not talking about making it a hot house with steaming vents everywhere. I am talking about adding just a little bit of moisture to the air. I actually have a really nice humidifier / dehumidifier in my darkroom and after years of use I have found I get the best results at around 15%-20 humidity.

    Remember that other things can cause curling too. Again using a heater or having excessively long wash times will definitely lead to more curling. As long as you use a weighted film clip, wash for the proper times and refrain from a heating device you should be ok. If you find your still having problems try a bit of humidity.
     

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