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  1. #1

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    C41: Artifacts from temperature and rough threading?

    Hello. I have just started developing C41 on my own, so please forgive the ignorance. I'm using the Naniwa Color Kit S with Porta 400. I have a theory about the artifacts I'm seeing, but I would like to confirm.

    1) In some of my negatives I have what seems to be a spotted discoloration that runs in a band across the edge of the film. I am doing two rolls of 120 together at once, which needs about 1000ml according to my canister, but I think the developer mix volume may be just under that, so the chemistry level inside the tank is too low, and the top piece of the film only gets saturated when I invert the tank every 30 seconds. Is this correct? (spottedBand.jpg)

    2) In the second set of negatives I developed I measured the temperate of the bath outside of the developer container, not the developer itself. As as a result I think the chemistry may have been more around 38 degrees C instead of 40. Visually the film ended up very light blue. Are color shifts like this the direct result of temperate errors in the chemistry? (temperature.jpg)

    3) Also, in certain rolls I have blue semi-circles and thick scratches (when scanned these become white marks since the color inverts). I've noticed this mostly on 220 film, which I have a hard time getting onto the reel inside of the changing bag. If I bend the film when loading onto the reel, would warps in the film cause these over-exposed spots, or is this due to something else? (scratches.jpg)

    Thank you for the help in advance, I'm running through 50+ rolls for a project I'm working on, and would like to take care these issues for good.
    Attached Thumbnails Attached Thumbnails spottedBand.jpg   temperature.jpg   scratches.jpg  

  2. #2

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    Hi, for the #3 the problem you kink the film in the loading process to mutch pressure on the film.

    #1 not enough chemistry or no agitation you see it's air bubbles.

    #2 if the base of the film is orange and the exposure neg is blue , the lighting is probably tungsten.

    Chamon

  3. #3

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    Hi, I can't answer the first two, except as guesses. But for #3, yes, kinking the film prior to processing can cause unwanted development to occur. It's called pressure-fog or pressure-sensitization. If you handle some film in the light, you'll find that it's pretty easy to put little kinks in it. They tend to take the shape of half-moons, just like in your example #3. I'm a bit surprised how many there are, unless you had to make 6 or 8 attempts to get the reel started.

    In addition to the half-moon kinks, there can be an assortment of pressure effects around scratches, etc. With the professional color neg films I'm most familiar with, very slight pressure marks, perhaps from a tiny burr (almost undetectable) in the camera, would cause slight yellow lines on the film (they show up as bluish lines on a print).

    Minimizing such pressure sensitivities is a big deal in film design, so you might find that professional films are less sensitive to this. Same thing happens with photo paper, too, but it doesn't tend to get kinked as much. (note: I see you're using Portra 400 film, this is probably among the best at resisting pressure-marks.)

    I think your best bet is to practice loading reels until you are just silky-smooth at it.

    One last suggestion I'd make is to not dump your used developer right away. Instead, pour it into a beaker (or the like), and hold it until you've looked at your developed film. That way, if anything unusual shows up, you still have the possible culprit. Otherwise, you have to say, well maybe there was not enough to cover the reel, or maybe it was bad developer, or whatever.

  4. #4

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    Air bubbles! That makes sense. Thank you chamon88! As for the blueness, it is possible. I have a new Metz strobe I don't know how to use properly yet. Thank you so much.

  5. #5

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    Mr. Bill, thank you so much for confirming my theory.

    I'm embarrassed to say 6 or 8 is on the low side... I have spent over 30 minutes on a single roll of 220 sometimes. I can do it just fine with a test roll in the light, but in the bag I find the film pops out of the grooves quite easily and I have to start over a lot. To check, I have started doing it with my eyes closed in the light, and when I feel it going wrong, looking down I see how the same problem happens in the bag. I just need to get better at protecting the film until it gets a full rotation through the reel and it settles down in the grooves. Thanks for the help!

  6. #6

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    I always had a hard time loading 120 or 220 film in a dark bag. 35mm was OK, but the wider film was more difficult. A Harrison film changing tent would be easier to use than a dark bag. They are expensive, unfortunately. Or you could light-proof a room or closet in your house or apartment temporarily whenever you need to load film onto reels. Or just practice with your dark bag a lot.

  7. #7

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    Quote Originally Posted by SingleLensSoul View Post
    Mr. Bill, thank you so much for confirming my theory.

    I'm embarrassed to say 6 or 8 is on the low side... I have spent over 30 minutes on a single roll of 220 sometimes. I can do it just fine with a test roll in the light, but in the bag I find the film pops out of the grooves quite easily and I have to start over a lot. To check, I have started doing it with my eyes closed in the light, and when I feel it going wrong, looking down I see how the same problem happens in the bag. I just need to get better at protecting the film until it gets a full rotation through the reel and it settles down in the grooves. Thanks for the help!
    I found plastic reels and tanks loaded 120 more easily than their metal counterparts. Once you slide the tongue over the ball bearings, it's a piece of cake (for me, at least). Of course, you pay with the inconvenience of having to wash and dry the tanks/reels very carefully, and you also use more chemicals than you would with steel.

    But it might be worth considering, because a half-hour struggle doesn't sound like fun.



 

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