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Thread: Blotchy pattern on 4x5 negatives

  1. #1

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    Blotchy pattern on 4x5 negatives

    I'm just getting started with 4x5 and I've been having an issue with a blotchy pattern on some of my negatives. My previous film darkroom experience was processing and printing B&W 35mm.

    I'm shooting Tri-X with a Toyo 45CF with brand-new Toyo holders, then processing myself in a Mod54 holder and Paterson tank, using D-76 (1:1) at the recommended developing time for the temperature. I'm agitating by using the rotary spindle on the Paterson tank (not inverting the whole tank).

    The problem only occurs on certain negatives - usually it's over the whole image, but one of my sheets had it just along one of the long edges. Most of my negatives have turned out normally. In a batch of 6 the ratio of good to bad might be 6/0 or 4/2. I also can't find a pattern as to where the sheet was in the Mod54 holder.

    If anyone has an idea where this might be coming from I'd appreciate any suggestions.
    Attached Thumbnails Attached Thumbnails SnagBlotchy.jpg  

  2. #2

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    Re: Blotchy pattern on 4x5 negatives

    may be chemical contamination of some sort, powdered fixer dust got on a sheet of undeveloped film.

  3. #3

    Re: Blotchy pattern on 4x5 negatives

    Try inverting the tank rather than the twirly thing. I invert my Paterson tanks - I have heard of issues supposedly resulting from using only the spindle. 30 seconds of inversion at the start, 3 inversions every minute thereafter.

  4. #4

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    Re: Blotchy pattern on 4x5 negatives

    Throw away that stick that twirls the reel!
    I used to collect these from students to prevent their use.
    Do as Stephen say 's - Invert. The 3 inversions should take about 5-6 seconds, in other words they are not lazy, but not overly rapid. If youwatch your timer as you do it, the inversions will become almost automatic.
    Back to your negatives - there was insufficient developer solution in the tank. The twirling made the curly patterns.

  5. #5

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    Re: Blotchy pattern on 4x5 negatives

    Michael, Stephen and Jim, thanks for the suggestions. If it's the agitation technique that's the problem, could it only affect certain sheets in the tank, like I'm seeing?

    One detail I forgot to mention that might be relevant is that I can see clear film on the edges of the sheet that were covered by the camera's film holder - the pattern is only found in the part of the sheet that was exposed by the camera. If it were the development would I not see it on the edges, since it also shows up in the clearest parts of the exposed negative?

    Not criticizing your interpretation, just want to understand.

    Click image for larger version. 

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  6. #6
    bw-man's Avatar
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    Re: Blotchy pattern on 4x5 negatives

    Film preservation reason?Affected by the wet?
    Film developing uneven mixing, a large area of influence.Transition boundary is gradual change, and is relatively fixed position.

  7. #7

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    Re: Blotchy pattern on 4x5 negatives

    Looks very odd indeed. I've never seen anything like that.
    Only thing that springs to mind is that you have been handling those negs with fingers contaminated with fixer or stop or possibly very sweaty fingers but they don't look like finger marks. Did you wash your hands very thoroughly and fully dry them before handling your film sheets? Are you careful not to touch the image area and only hold film by the edges? Did it only happen after you had been putting your fingers in dev/stop/fix solutions?

  8. #8

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    Re: Blotchy pattern on 4x5 negatives

    I virtually always "stick twirl" my Paterson development tanks. Works like a charm, but we've seen many times before on this forum what works perfectly for one person, gives another person endless trouble. Still, given the nature of these defects, I'd look in other places than the mode of agitation.

    Do you pre-soak the film? Do you rinse the tank and it's innards after a development session to ensure no photo Flo remains in them? What is your agitation scheme?

  9. #9

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    Re: Blotchy pattern on 4x5 negatives

    If its only happening on one or two negs in a tank with 6 sheets of film in I'd say its nothing to do with developer strength. The twirl stick never did work with film on spools becasue it just twirled the center column and not always the spools. Not sure with the mod54 but it looks the same, i.e. the center column could rotate inside the mod54 so personally I wouldn't use a twirl stick.
    It could be sheets of film coming into contact with each other as you twirl.
    Did the sheets come out after developing still in their corrects slots? Did you load the mod54 with sheets in correct slots in the first place?

  10. #10

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    Re: Blotchy pattern on 4x5 negatives

    The twirl stick never did work with film on spools becasue it just twirled the center column and not always the spools.
    It does with my spools, tanks and mod54. The Mod54 fits snugly over the center column, as do the Paterson spools I use. It can be easily checked by doing a test run with the top part of the tank removed.

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