Up-swept HD curve

Discussion in 'B&W: Film, Paper, Chemistry' started by polyglot, Oct 11, 2011.

  1. polyglot

    polyglot Member

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    Efke IR820 has it in spades. Hurrell's film clearly had it. Older TXP apparently somewhat had it; current TXP in sheets may or may not still do it depending on who you ask.

    Is there a film I can buy (I haven't tried R100/PL100 but the published curve is a lot straighter than for IR820) or processing technique that I can use to get a fairly long toe with a dramatic upsweep in the middle of the HD curve?

    I've tried (semi-)stand development in Rodinal 1+100 and found that it gives the long toe but I also found that the compensation effect introduces significant shoulder so the highlights look quite dead. I want the curve to shoot up steeply as it goes through Zones VII-IX at least, without any apparently shouldering.

    I can fake it easily by scanning, but obviously want to be able to do it with an all-analogue process.
     
  2. john_s

    john_s Subscriber

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    HC-110 has a reputation for producing an upswept curve, according to

    http://www.covingtoninnovations.com/hc110/

    Ryuji Suzuki suggested TMax400 for this sort of curve. Maybe this pair is worth a try. Maybe box speed and generous development, not with a highly dilute developer? Just guessing.
     
  3. hpulley

    hpulley Member

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    Some complain about it but HC-110 gives an up-swept curve.
     
  4. polyglot

    polyglot Member

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    Interesting. I shall have to add a bottle to my next chemistry order.
     
  5. michael_r

    michael_r Subscriber

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    Using higher concentrations of MQ/PQ developers tends to result in less speed and higher highlight contrast. That is what would generally be referred to as an upswept curve.
     
  6. MattKing

    MattKing Subscriber

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    Somewhere here on this site there is discussion about using TMax 100 (I think) exposed at 200 and pushed to 400 ISO in HC110 to emulate TXP 320's upswept curve (IIRC).

    No promises - I haven't tried it myself, and my memory certainly isn't perfect.
     
  7. michael_r

    michael_r Subscriber

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    It might have been Thomas Bertilsson. I seem to remember he was using a certain combination (perhaps TMY and HC110 or XTOL, can't remember for sure, or maybe it was even Acros exposed at 200). Try searching the threads.
     
  8. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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  9. polyglot

    polyglot Member

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    Thanks, Thomas. Do you have any examples where it shows the very sparkly highlights (example with IR820) instead of flat lighting, and/or an HD plot?
     
  10. brian steinberger

    brian steinberger Member

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    If you're looking for an upswept curve from a panchromatic film that looks similar to IR820 I'm afraid you're just not gonna get it. Sure we can push films and overdevelop them but we're still not gonna get those glowing highlights you get with IR film, not to mention its very unique spectral sensitivity (vegetation goes white).

    An upswept curve is something I've experimented with for quite a while. TMAX 400 pushed to 800 and developed in a speed increasing developer like Xtol 1:1 works ok, but lacks a bit too much shadow detail for me. Another combo that I've used to get a good upswept curve is Tri-x (TX, not TXP) in HC-110, especially pushed to EI 800.
     
  11. MattKing

    MattKing Subscriber

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    Thanks Michael and Thomas - good to know that my memory is almost accurate :smile:.
     
  12. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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    No. I don't. My photography life is mostly about shooting and very little about testing, so the example shown is the only one, and likely the only one I'll ever make.

    - Thomas
     
  13. ic-racer

    ic-racer Member

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    I'm not sure why one would want a curve like that. The mid values will print too dark. This is one curve I got, with some combination of elements I won't use again :smile:
    [​IMG]
     
  14. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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    Low contrast lighting and portraiture, for two.

     
  15. rmolson

    rmolson Member

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    Upswsept curve

    Upswept curve


    This may be bit off the topic but for years I bemoaned the loss of the old FP4 withD761:1 that would give me a bump in the straight line at the mid tone, lightening ever so slightly Zone V without affecting the highlights and shadows Present day FP-4+ while very good, doesn’t possess this quality. I had a densitometer and plotted curves in those days. over exposure and underdevelopment does not give the same result. It bends the full curve. We use to use that technique masking reflection copy in color separation. Not the same thing .On a the high end drum scanner we could do it as we had a five point scale to work with
     
  16. michael_r

    michael_r Subscriber

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    In general the current versions of conventional films like Tri-X, FP4, HP5 etc are longer-scale and straighter-lined than their previous incarnations. Essentially they are less conventional than they once were, relative to their flat grain counterparts. My understanding is this is mostly because the technology involved in flat grain films (ie flatter grains, more dye sensitization, less silver) has been applied, to some extent, to the conventional films as well. Depending on your personal taste these are either improvements or not.
     
  17. TheFlyingCamera

    TheFlyingCamera Membership Council Council

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    You could always give the Fomapan 200 a try- it is very easy to build contrast with it for alt-process printing, so it might do what you need. Expose it at 100, to make sure you get decent shadow detail, then overdevelop by 50% or even more.
     
  18. michael_r

    michael_r Subscriber

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    Another thing to try would be Acros, rated at box speed or a bit higher, developed in virtually any standard PQ/MQ developer. Rating it at box speed or higher will introduce more of a toe on the low end. The film naturally has very high highlight contrast, in fact higher contrast there than in the midtones. So combining all these elements you'd have a sort of upswept curve. It's a flat-grain film though, so it would never really look like Tri-X etc.
     
  19. Ryuji

    Ryuji Member

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    Try Acros or T-MAX 400 in full strength film developer. You may have to overexpose because you won't get long toe.
    Don't do semi-stand. Do Kodak agitation method every 30 sec or use continuous agitation.
    If you are doing studio portrait like George Hurrell's classic headshots, it has a lot to do with lighting as well. Many portrait photographers today are not bold enough to use specular lights like his era. Put your softbox and shoot-thru's and switch to shiney metallic parabolic reflectors, especially the hair light. Be careful about the lens flare, especially if you use vintage lens. Any straight line film would be made to look reasonably darker midtone and harsh highlight like this... If the skin comes out too shiney/dewey use water based airbrush makeup and/or mattifying gel on the skin.
     
  20. JaZ99

    JaZ99 Member

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    This is one of my first experiments with Acros, Rodinal, low temperature and minimal agitation:

    Acros-Rodinal-18min.png

    The curve shape is very peculiar. Perhaps I need to repeat it.