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Thread: Very High Brightness Range

  1. #1

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    Very High Brightness Range

    Hi

    I've been trying to capture a scene with texture in a brightness range from around EV 2.5 to EV 16 but without getting a useable neg and I'd like to ask your advice on how to improve my success rate!

    The story so far... I'm using 5x4 TMX (possibly not the best film in the situation but the only one I've got); I've tried exposing (on separate negs!) for both the shadows (placing EV 2.5 on Zone II) and the highlights (EV16 on Zone IX or X) and processing in either highly dilute Rodinal (1+200 stand development for time from 30 mins) or DDX 1+4 at ridiculously short times trying to emulate N-4. When I can get the highlights under control it's at the expense of any shadow detail at all. Or mid-tone detail come to that!

    Any assistance greatfully received.

    Thanks, Ian

  2. #2

    Very High Brightness Range

    You must lower the ISO of the film if you are going to do minus development. Testing of your materials is the only way to know how much. The shadows will fall also (though to a lesser extent than the highlights), so you have to start higher. In lieu of comprehensive testing you might try to place your important shadow detail on Zone V and do the same stand development.

    Please, don't try this with irreplacable negatives.

  3. #3

    Very High Brightness Range

    Hi Ian,

    You could try a pre-flash before the main exposure along with a metol only developer such as D23 (avoid hydroquinone as it builds contrast). Two bath developing may also help although it'll be similar to stand development. Someone who uses TMX more than I should be able to tell you more about how the film responds and how far you can go with minus development. Printing might prove interesting.

    Regards,

  4. #4

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    Very High Brightness Range

    Henry, thanks.

    I didn't mention it but I've been trying with the TMX at EI 50, 64 and 80 without much success.

    Another question for you... if I place the shadows on Zone V, as you suggest for the stand development, won't this result in even less exposure for those so-far-missing low values and push the highlights even further up the scale?

    My testing technique is basically trial and error so for me comprehensive testing means patience and few more wasted sheets. Or I could stop being stubborn and go find a less challenging scene...

    Ian

  5. #5

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    Very High Brightness Range

    Sounds like a job for POTA, or a similar compensating developer, but an 18 stop range is extreme for any film/developer combination. I think it might require a combination of pre-exposing your film, and developing in a highly compensating developer, but without testing, It's a longshot. Good luck.

    Jay

  6. #6

    Very High Brightness Range

    Exposing the shadows for Zone V will give more exposure everywhere. So there will be more density in the shadows - not less - and the highlights will get pushed further up the scale also. But TMX has a pretty long straight line, so the highlights might well be OK.

    Don't give up on the scene, especially if you can go back and create more negatives under the same conditions. Learn to deal with it as best you can; it will likely happen again.

  7. #7
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    Very High Brightness Range

    Hi Ian,

    Using TMX film with a scene of such high contrast, and attempting to tame those blown-out highlights, is an exercise in futility. Select a different film. There are many more choices available, in both film and developers, that are better suited for that type of subject.

  8. #8

    Very High Brightness Range

    Hi there,

    You could try RA4 bleach/fix as a proportional reducer, test times on the scrape negs.

    You could try the classic 5g metol+ 100g sulfite /1.oL water, try 20 minutes as a start time.

    I think TMX has about the longest straight line curve for any film on the market, it should handle the scene if any film can.

    Good Luck with it.

  9. #9

    Very High Brightness Range

    I have tested TMY for an SBR of 18.6 which is what you need for your neg. My EI for TMY at this range is 40 and I develop for 2 min with constant agitation at 74 ºF in pyrocat HD. YOu dont mention what developer you use, but you might want to try exposing TMX at an EI of 6 and developing for 1.5 to 2 min.

    Good luck and let me know if it works out...

  10. #10
    Resident Heretic Bruce Watson's Avatar
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    Very High Brightness Range

    I suspect that the easiest way to deal with this is going to involve some digital work. If you are up for it, here's a workflow that might work for you:

    1) Expose for the shadows and let the highlights fall where they may. Develop at N-2 or better. In other words, get this sheet's Dmax down as much as you can, but don't obsess about it.

    2) Drum scan the resulting negative. The drum scanner will be able to read through the negative's Dmax, whatever it might be, and fit the negative's dynamic range into the 0-65535 digital range. A 16-bit grayscale scan will probably do nicely for you.

    3) Pull the resulting file up in an image editor and clean it up. That is, crop it, spot it, set your levels and apply whatever curves you need. If the negative needs work on local areas (dodging, burning, whatever) do that too.

    4) Output to 4x5 film with a film recorder. Alternatively, output to an inkjet printer or B&W photopaper on a Lightjet or Chromira printer.

    5) If your output was film, take it back to the darkroom and print it normally.

    There are many ways to do it; this is just one. Clearly, YMMV.

    Bruce Watson

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