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  1. #11

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    Quote Originally Posted by Chris Breitenstein View Post
    Pre-soaking allows the developer to penetrate the film more quickly and more evenly. While some may see this step as unnecessary, If you are are working with a thick emulsion film like Efke, failing to prewash may mean that the silver on the surface of the emulsion is getting far more development then silver closer to the film base. This results in images that are much sharper, but do not utilize the potential tonal scale.

    yours;
    i've found, by accident, that you can take advantage of this for good effect. i just let a peice of sheet film float on top of the developer (Rodinal), with emulsion on top and not even touching the developer. the developer penetrates into the emulsion from the thick base of sheet film. i get really incredible accutance and the development time is only 1 minute longer than usual.

    so i can imagine that pre-wetting might be bad for accutance as all that concentrated developer hits the film emulsion at once.

  2. #12

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    Quote Originally Posted by cotdt View Post
    i've found, by accident, that you can take advantage of this for good effect. i just let a peice of sheet film float on top of the developer (Rodinal), with emulsion on top and not even touching the developer. the developer penetrates into the emulsion from the thick base of sheet film. i get really incredible accutance and the development time is only 1 minute longer than usual.

    so i can imagine that pre-wetting might be bad for accutance as all that concentrated developer hits the film emulsion at once.
    That has not been my experience. I always do a 5 minute soak in tempered water before developing - and I develop stand or semi-stand to high acutance with highly diluted developers.
    Tom Hoskinson
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  3. #13
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    Quote Originally Posted by cotdt View Post
    i've found, by accident, that you can take advantage of this for good effect. i just let a peice of sheet film float on top of the developer (Rodinal), with emulsion on top and not even touching the developer. the developer penetrates into the emulsion from the thick base of sheet film. i get really incredible accutance and the development time is only 1 minute longer than usual.

    so i can imagine that pre-wetting might be bad for accutance as all that concentrated developer hits the film emulsion at once.
    For film, this observation is totally impossible!

    Developer cannot penetrate the film base. So, if you observe development, it is being caused by some other method.

    The positioning /overcoat/emulsion layer/support/~developer~ will not sustain development in any way possible, as the hydrophobic support will not allow the water to penetrate. The same is true of RC support. With FB paper this is possible.

    PE

  4. #14

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    I'm new to developing my own film (will start within a week or two after my exams), so please bear with me!

    What exactly does the anti-halation layer do and is it only on one side of the film? I shoot primarily 120 film and 35mm film and was wondering if it's OK to touch the back of the film while rolling the film onto the reel. Will this cause fingerprints to show on the print? Or will the anti-halation layer allow me to touch the back of the film because I will simply be washing it off (I will be practicing the pre-soak method)?

    Thanks,

    Jason

  5. #15
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    Jason;

    All interfaces in film act like mirrors, so the emulsion/support interface is like a mirror that bounces light back to the emulsion creating flare and loss in sharpness. All manufacturers add acutance dyes to the emulsion layers and then add an AH layer to prevent this scatter and flare. Some of them add a tiny amount of carbon to the film itself creating an AH effect while at the same time decreasing the chance of static discharge as well.

    PE

  6. #16
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    --------------------------------------------------------------------------------

    Quote:
    Originally Posted by cotdt
    i've found, by accident, that you can take advantage of this for good effect. i just let a peice of sheet film float on top of the developer (Rodinal), with emulsion on top and not even touching the developer. the developer penetrates into the emulsion from the thick base of sheet film. i get really incredible accutance and the development time is only 1 minute longer than usual.

    so i can imagine that pre-wetting might be bad for accutance as all that concentrated developer hits the film emulsion at once.

    For film, this observation is totally impossible!

    Developer cannot penetrate the film base. So, if you observe development, it is being caused by some other method.

    The positioning /overcoat/emulsion layer/support/~developer~ will not sustain development in any way possible, as the hydrophobic support will not allow the water to penetrate. The same is true of RC support. With FB paper this is possible.

    PE

    I agree also if the developer did soak into the base you would have to wash the film forever just like fiber paper, not 10-15 minutes.

  7. #17

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    Quote Originally Posted by Photo Engineer View Post
    Jason;

    All interfaces in film act like mirrors, so the emulsion/support interface is like a mirror that bounces light back to the emulsion creating flare and loss in sharpness. All manufacturers add acutance dyes to the emulsion layers and then add an AH layer to prevent this scatter and flare. Some of them add a tiny amount of carbon to the film itself creating an AH effect while at the same time decreasing the chance of static discharge as well.

    PE
    Thanks for the info PE. So this means that I could touch the anti-halation layer and it should not affect the image quality right? I won't be man handling the thing, but in case I need to reposition things here and there...

    I've never done this before, so I was just wondering

    Thanks again,

    Jason

  8. #18
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    Quote Originally Posted by jasonjoo View Post
    Thanks for the info PE. So this means that I could touch the anti-halation layer and it should not affect the image quality right? I won't be man handling the thing, but in case I need to reposition things here and there...

    I've never done this before, so I was just wondering

    Thanks again,

    Jason
    Jason;

    Touching film is not a good idea in any case if you wish to image on it after touching it. There are many reasons, but mainly the salt and the oil in skin will affect the emulsion and the ability of the emulsion to develop.

    PE

  9. #19
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    Normally, I never, ever touch the emulsion side of the film and I try to avoid touching the back of the film too except when I am loading it onto stainless steel reels. I usually hold the film from its edges as i do this but i occasionially place a finger on the back of the film as i roll it onto the reel just to make sure it is going on straight. I havent noticed any fingerprints whatsoever on the negatives. Just make sure your hands are nice and clean and dry.

  10. #20

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    Thanks for the heads up guys. I won't be using a changing bag, so maybe a pair of nitrile gloves. While I haven't tried putting film on a reel yet, I'm sure it would be even more difficult with gloves on. I'll give it a go in a week or two!

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