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  1. #21
    Photo Engineer's Avatar
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    I don't see how higher contrast would help. That is what to expect with a push.

    Looks good to me.

    PE

  2. #22

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    Yeah, your right. This is a definite improvement over what I was getting for sure. I don't want more contrast.

  3. #23
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    Okay, I just did a test out of curiousity's sake.

    I shot some Lucky 200 (C-41 film of course) at 200, 400, 800, 1600, and 3200 repeatedly, cut the roll in half, loaded 1 in C-41, then stand developed other half in Rodinal 1+100 for 10 minutes, stopped, then washed the film and dried it in the dark, I cut one from off and examined in the light, there's a good visible B&W negative. Once dry I then processed it through C-41.

    The Rodinal pre-treatment half has lower density than the C-41 only shots - on 200, mainly in the shadows - and signifnicantly noticeable lower density over all in the 3200 shot.


    This isn't a case of the B&W dev taking up too much of the available halide, otherwise the 3200 shot would be less affected not more.

  4. #24

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    That's really interesting, so it appears the effect is higher on areas with lower exposure so the rate of development could be expressed as a logarithmically regressing curve with local exposure on the x axis development rate on the y...... I would have thought 10 minutes to be insufficient to produce much of a result at that high dilution. What is the impact on overall image quality? Is there an improvement in the grain appearance? Is the color affected much?

  5. #25
    Athiril's Avatar
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    It's kind of like a restraining action, but less effect on higher exposed areas than usual, I'll scan them tomorrow. I haven't looked at image quality. I'm wondering if I can use this to increase colour contrast.

    I only inspected them on a light table, and can notice large density difference.

    I imagine the majority of development occurs early in 1:100, then slows down for rest of stand, as it's not diluted enough for slow development

  6. #26
    Athiril's Avatar
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    C-41 Control 3200


    Rodinal pre-treatment + C-41 3200



    These scans were done raw, the C-41 control had levels applied in Photoshop for a basic balance, then the same levels settings were applied to the Rodinal pre-treatment, to show the relative difference between the two.


    The Rodinal pre-treatment + C-41 seems to hold slightly better shadow detail, significantly better grain, and appears as if it would support moderately better image detail.


    Here are some crops (from a high end scan), these were re-levelled individually this time quickly
    C-41 control 3200


    Rodinal pre-treatment + C-41 3200



    Should also mention Rodinal forms some very weak colour dye, though when I've tried to use it before, it all but disappears after a bleach and fix. Here is a shot at 200, that only had Rodinal 1+100 10 min stand, stop, wash and dry (no bleach or fix).




    Apart from a colour difference between the two 200 shots, I cannot find any other significant difference in image quality. The difference between the 200 and 3200 Rodinal pre-treatment shots being that the 200 would have received a lot more development and density than the small amount the 3200 would have gotten, perhaps the same difference in grain could be achieved with much less development in Rodinal at box speed, and I wonder how it would compare to a solvent type developer pre-treatment.
    Last edited by Athiril; 03-18-2014 at 09:12 PM. Click to view previous post history.

  7. #27
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    These are very nice results, I will probably repeat them with Portra 400 and Superia 800 soon. Since your EI3200 sample looks a bit low in contrast, I wonder how it would look after an 1-2 stop push.

    Right now we have two theories about how this Rodinal pretreatment works: contrast reduction in the highlights, or activation of barely exposed grains. A nice way to find which one is correct would be repeating that test with dilute PC-TEA. PC-TEA is known to give higher emulsion speed than Rodinal and also contains no solvent, so its effect on shadow detail in this process would be revealing.
    Trying to be the best of whatever I am, even if what I am is no good.

  8. #28

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    Any point of experimenting with something like process it in Diafine or Emofin first, as they are known to work well with high ISO / underexposure, and then process in C-41 per normal?

    I am asking only because I have some Diafine in the jugs :-)

  9. #29
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    I think best results would be obtained by pre-flash + pre-treatment with B&W dev + long push in C-41, as pre-flash + long C-41 push has given the best high speed results so far for speed and quality (it's on page 2 of this thread), this eked out a little more 'natural' speed, so may give more with pre-flash + push, as well as finer grain.

    Emofin will develop a colour negative already I think, as iirc it has a PPD based developer in it.

    Diafine will give too strong of a negative I think (at least for box speed), as I found no improvement at box speed, box speed shot had a much stronger b&w neg than the 3200 one. I suspect best results are obtained with a very weakly developed b&w negative. You can always give it a go, just bracket it.

    At the very least, you'll get finer grained shadows in extreme low exposure zones at box speed doing the above.

    I wouldn't mind trying a more dilute split-bath type developer, or a very dilute version of an xtol type developer with some solvent added. I think some type of extreme compensating developer that's limited to forming only very low density would be good to try.

  10. #30

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    Wow, these are the exact results I was hoping to see. The grain structure is significantly more appealing at ISO 3200 with the Rodinal pretreat, the same effect as it has in Tri-X I've shot at ISO 3200. The grain is there but it appears smaller and the color noise in the dark areas seems more appealing as well. It also appears the color changes are manageable, nothing went to wonky. Thanks for checking this out. I would have probably toasted my first try since I was thinking 30 minutes pretreat. 10 minutes in Rodinal 1:100 followed by normal C-41 seems to be right on the mark.......... Looks like a winner.

    Quote Originally Posted by Athiril View Post
    C-41 Control 3200


    Rodinal pre-treatment + C-41 3200



    These scans were done raw, the C-41 control had levels applied in Photoshop for a basic balance, then the same levels settings were applied to the Rodinal pre-treatment, to show the relative difference between the two.


    The Rodinal pre-treatment + C-41 seems to hold slightly better shadow detail, significantly better grain, and appears as if it would support moderately better image detail.


    Here are some crops (from a high end scan), these were re-levelled individually this time quickly
    C-41 control 3200


    Rodinal pre-treatment + C-41 3200



    Should also mention Rodinal forms some very weak colour dye, though when I've tried to use it before, it all but disappears after a bleach and fix. Here is a shot at 200, that only had Rodinal 1+100 10 min stand, stop, wash and dry (no bleach or fix).




    Apart from a colour difference between the two 200 shots, I cannot find any other significant difference in image quality. The difference between the 200 and 3200 Rodinal pre-treatment shots being that the 200 would have received a lot more development and density than the small amount the 3200 would have gotten, perhaps the same difference in grain could be achieved with much less development in Rodinal at box speed, and I wonder how it would compare to a solvent type developer pre-treatment.
    Last edited by Lamar; 03-19-2014 at 04:33 AM. Click to view previous post history.

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