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  1. #11
    tiberiustibz's Avatar
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    So the first development develops almost all of the exposed halide. The red re-exposure exposes all the red sensitive halide which is developed in cyan developer. The blue re-exposure exposes only the uppermost layer because directly below it is a yellow filter layer, which is developed in yellow developer. The rest is chemically fogged and developed in magenta.

    To answer your question, there will always be color crossover where dyes are developed in incorrect layers. The goal of good K14 processing is to minimize that effect.
    --Nicholas Andre

  2. #12
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    First development goes to completion and then some due to its being a solvent developer. This leaves just the right amount of "positive" silver left to image correctly.

    The red layer on the bottom is exposed through the base to very narrow cutting red light exposing only the red layer and then all of the red sensitive Silver Halide is developed. Then the blue sensitive layer is exposed through the top and the blue sensitive Silver halide is developed. The yellow filter layer protects the green sensitive layer from light reexposure. Finally, the film is fogged chemically and the film is developed in the final developer.

    Throughout this, scavengers and competers are present to prevent color formation in the wrong layers just in case.

    PE

  3. #13

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    Thanks for that explanation. However, if "normal" development is carried out to completion, how, then, is "push-processing" of Kodachrome done?

  4. #14
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    The silver halide solvent dissolves and redeposits more silver on the negative image and the negative image also goes into fog. This brings the Dmin of the negative up and thus the Dmax of the positive comes down. So, in the final slide the blacks can be gray if the push is strong enough. Also, contrast and color saturation change.

    As the Dmax of the positive decreases, the overall impression is that the image becomes lighter (pushed) when what is really being accomplished is just Dmax reduction. There is no real gain in speed, just an apparent change in the mid tones.

    PE

  5. #15

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    That's interesting, thank you...I think I understand. It seem quite different to pushing B&W negative film.

    It all just confirms what a remarkable process Kodachrome is...I admire the people who thought it out and improved it over the years.

  6. #16

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    Not actually directly concerned with this thread, but on the rare occasions that I try to start a new thread rather than reply to an existing one, I ALWAYS have trouble working out how to start a new thread and on this occasion have given up! Could there not be a button in the header bar that says "Start New Thread"?

    Anyway, I spent part of the weekend just gone shooting my last roll of Kodachrome. I agonised for some time what should be the contents of The Last Roll, but eventually decided that I'd just go out and shoot the kind of subjects that I typically did in the days when I used Kodachrome exclusively (which actually much the same old stuff that I shoot now!). Thus I took myself off to Cornwall and shot a good many mining remains. In doing so, I found myself thinking about the deadline for getting the film to Switzerland for onward shipment to Dwayne's. I couldn't help wondering, as the Day of Reckoning approaches, surely Dwayne's is going to be snowed under with work. Can anyone 'in the know' say whether Dwayne's are gearing up for this influx of work? I imagine that there could conceivably be a large number of disappointed people who may have sent films in good time but don't get them back processed.

    Apologies if this has already been discussed (it probably has) but there's so much Kodachrome correspondence to search through here!

    Best wishes,

    Steve

  7. #17

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    Thank you PE for your explanation, it makes sense!

    How about pull processing? I once shot a roll of K64 at EI 32 and had it pulled one stop. I was disappointed that there was a slight cyan cast to the images. I didn't ponder the actual reason for it then, but I now realize it is indeed consistent with my theory that leftover developable halide after the first developer results in a thin cyan colored negative image in all layers later. Is this what happened to me, or is there another reason behind the color cast?

  8. #18

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    Quote Originally Posted by Steve Roberts View Post
    I couldn't help wondering, as the Day of Reckoning approaches, surely Dwayne's is going to be snowed under with work. Can anyone 'in the know' say whether Dwayne's are gearing up for this influx of work? I imagine that there could conceivably be a large number of disappointed people who may have sent films in good time but don't get them back processed.
    I've no inside knowledge at all, but FWIW I'd guess that there might not be any significant last-minute-rush. I'd think that most Kodachrome this year has probably been shot by enthusiasts like ourselves, who have planned their photography throughout the seasons and have been well aware of the final processing date. My own Kodachrome shooting should be completed in the next couple of weeks, in time to get the film to Lausanne before the 30th, and I should then have very little film left....if I do have a couple left over in December, I won't be too worried. I'd rather keep them in honourable retirement as museum pieces, rather than deliberately waste them on rubbish shots.

    To be fair, Kodak have handled the end of European film as well as could be expected, and I'm sure that they and Dwaynes will honour the final dates for receipt of film, even if they have to run the processing line for a day-or-two into January.

  9. #19
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    Quote Originally Posted by Fredrik Sandstrom View Post
    Thank you PE for your explanation, it makes sense!

    How about pull processing? I once shot a roll of K64 at EI 32 and had it pulled one stop. I was disappointed that there was a slight cyan cast to the images. I didn't ponder the actual reason for it then, but I now realize it is indeed consistent with my theory that leftover developable halide after the first developer results in a thin cyan colored negative image in all layers later. Is this what happened to me, or is there another reason behind the color cast?
    Pull processing underdevelops in the first developer giving a weaker negative image. This leaves more Silver Halide to form dyes in the color developers. Since development is diffusion related, I suspect that the cyan (bottom) layer was the most weakly developed and therefore in the reversal process formed more dye giving a cyan cast. By this same reasoning, a push would tend to give warm images.

    PE

  10. #20
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    Quote Originally Posted by Steve Roberts View Post
    Not actually directly concerned with this thread, but on the rare occasions that I try to start a new thread rather than reply to an existing one, I ALWAYS have trouble working out how to start a new thread and on this occasion have given up! Could there not be a button in the header bar that says "Start New Thread"?

    Anyway, I spent part of the weekend just gone shooting my last roll of Kodachrome. I agonised for some time what should be the contents of The Last Roll, but eventually decided that I'd just go out and shoot the kind of subjects that I typically did in the days when I used Kodachrome exclusively (which actually much the same old stuff that I shoot now!). Thus I took myself off to Cornwall and shot a good many mining remains. In doing so, I found myself thinking about the deadline for getting the film to Switzerland for onward shipment to Dwayne's. I couldn't help wondering, as the Day of Reckoning approaches, surely Dwayne's is going to be snowed under with work. Can anyone 'in the know' say whether Dwayne's are gearing up for this influx of work? I imagine that there could conceivably be a large number of disappointed people who may have sent films in good time but don't get them back processed.

    Apologies if this has already been discussed (it probably has) but there's so much Kodachrome correspondence to search through here!

    Best wishes,

    Steve
    Steve:

    You need to be in the "list of threads in a forum" area to start a new thread, not in a thread that is part of the forum.

    Click on the forum title near the top of the screen and it will take you to that forums list of threads. Then, again near the top of the page you will see a grey box that contains the words "+POST NEW THREAD". Click on that box, and you are off!

    You can also get to each forum individually by clicking on the "Forum" tab at the top of the screen, moving through the list of forum headings, and then clicking on the forum title itself.

    As to your question - I expect Dwayne's has a certain amount of chemistry on hand, but that Kodak has most likely committed to provide whatever additional chemistry will be required to develop all Kodachrome in Dwayne's hands as of close of business on December 30th.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

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