Film Loosing or Increasing Speed During Development Question

Discussion in 'Talk About Developing Film' started by Ian-Barber, Jan 23, 2018.

  1. Ian-Barber

    Ian-Barber Admin Staff Member Registered User

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    As I read various books or articles online, I often come across the phrase, "During development, the film may lose speed".

    Does this mean that the developed negative may appear darker in the lower regions?
     
  2. Ian Grant

    Ian Grant Active Member Registered User

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    No it just means that the emulsion is becoming less sensitive to light (ie dropping in speed), this was more important when glass plates were developed by inspection. This is in the days before meters and less control over the emulsion making leading to speed variations between batches.

    Ian
     
  3. Ian-Barber

    Ian-Barber Admin Staff Member Registered User

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    Would it be fair to assume that today with modern materials, these issues are not something we should be concerned about.
     
  4. David M

    David M Well-Known Member Registered User

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    It does mean that you can develop film by inspection in a dish. I know someone who routinely did this. You develop for a time in total darkness, but it needs practice to put on the safelight briefly and recognise the progress of the negative. I'm told that the appearance of the back of the neg is a more reliable indicator. There's something called emergence time (?) that you have to watch for. I haven't dared to do it myself so I can't comment.This is all I know.
    It does explain how you can remove film from BTZ tubes before fixing, if I understand accounts of the process that I've read.
     
  5. Alan9940

    Alan9940 Active Member Registered User

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    During DBI (development by inspection), one looks for the correct appearance of highlights (Zone VIII level highlights, not specular) through the back of the negative. Personally, I found this difficult to judge under the brief few seconds the safelight was on. Additionally, I never really understood how one might see the difference between, say, 1.25 negative density and something that might be too much density; maybe, 1.50.
     
  6. David M

    David M Well-Known Member Registered User

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    My understanding of the significance of emergence time is that you noted how long it took for the darkest parts of the neg to appear, from inserting the film into the developer, then did some rapid mental arithmetic to multiply by a factor which gave you a total development time for that particular sheet, in that particular batch of that particular developer, at that particular temperature. Sadly, I forget how you determined this magical factor but I presume something like a Zone-testing procedure would be needed. I also presume that, as Alan points out it would be difficult to decide what the exact point was, but many things can be accomplished by practice. 10,000 hours to become a concert pianist! Guessing a black might be quicker.
    On Another LF Forum I have heard of infra-red goggles being used. Does anyone here have experience?
    On another of Alan's points I don't know that the absolute density of parts of a negative is important, but only that the tones should have a proper relationship to each other (within the limits of printability, of course.) I hope this makes sense. I stand open to correction on this.
     
  7. Ian-Barber

    Ian-Barber Admin Staff Member Registered User

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    If certain developers make the film become less sensitive to light during the development stage, should we be doing anything at the exposure stage to allow for this ?
     
  8. Ian Grant

    Ian Grant Active Member Registered User

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    No, it doesn't really work with modern films which are very much faster and you were supposed to add a dye de-sensitiser like Pinacrytol Green.

    Ian
     
  9. Alan9940

    Alan9940 Active Member Registered User

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    "within the limits of printability" is the key point IMO. The only tones you can see are the darkest tones which represent the upper end of the zone scale; basically, Zone VIII and above. And, for the brief few seconds that you have the light on, you cannot see texture in those tones. Can you tell the difference...in the dark...with a dim 15-watt light at about 4 feet...for about 3 secs...between Zone VIII and Zone IX? The former where you'll still have some texture and the latter where it's basically gone? I spent many hours desperately trying to master DBI with HP5+ and Pyrocat-HD because I thought it was the perfect solution to the wild swing in darkroom temps I see throughout the year. Simple, right? Just develop the neg for as short or as long, as needed. Maybe it's just me, but I just couldn't get to where I wanted to be; I returned to time/temp development.
     
  10. Stephen Batey

    Stephen Batey Well-Known Member Registered User

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  11. David M

    David M Well-Known Member Registered User

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    Alan,
    I must emphasise that I'm not speaking from direct experience, but only reporting my recollections.
    The assumption behind watching for an emergence point is that it is a pragmatically reliable indicator of the progress of development and would be visible with a brief glance. I'm afraid I don't see how one could distinguish between ZVIII and ZIX in a closed tank at all. Tank development gives no clues to the progress of development and relies on dead reckoning.
    Edward Weston used inspection for development, so it does seem that it is possible to produce a very high standard of work, without knowing specific negative densities.
    In his Daybooks, he makes a brief reference to "demonstrating the desensitising technique" (presumably as described by Ian) but this doesn't seem to have been his normal practice.
    Might I mention that tennis players don't rely on instrumentation for the force and direction of their return, but make very precise judgements rapidly, using experience and direct sensory feedback. The fact that they mostly get it right is what makes tennis so boring. We can easily imagine that Edward "knew" when a neg looked right.
     
  12. David M

    David M Well-Known Member Registered User

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    I have found a reference to emergence in Way Beyond Monochrome, page 340. but this relates to printing not negative development. He calls it Factorial Development. Apparently, you look for the emergence of Zone V, note the time and multiply by a factor that you've previously determined experimentally. This apparently ensures that the print, which is already visible under the safelight, is properly developed. Hmmmm...
     
  13. Ian Grant

    Ian Grant Active Member Registered User

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    Ralph over develops his prints, way past the manufacturers recommended times, this would kill the warmth of a warm tone paper and have an effect on the highlights and mid-tones.

    Ian
     
  14. David M

    David M Well-Known Member Registered User

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    It seemed a very peculiar recommendation anyway. How is one to distinguish ZV emerging in a dish under safe lighting? All tones must begin to appear as ZVIII or ZIX-ish. I have sometimes hung on beyond normal times in the hope of squeezing a bit more out of the highlights. I came across an old-school photographer who breathed on his highlights. For all I know, nicotine or alcohol fumes may have an effect.
    If we return to (the other) Ian's original question, about film losing sensitivity in the developer, which I think has been dealt with, it did cross my mind that if you were contemplating Sabattier ("solarisation") effects on film, then progressive changes during development might be relevant.
     
    Last edited: Jan 27, 2018
  15. David M

    David M Well-Known Member Registered User

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  16. Alan9940

    Alan9940 Active Member Registered User

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    David M,
    I am speaking from my own direct experience. Maybe I've left the wrong impression in my comments... DBI is not difficult and it's easy to determine a general development time based on experience. What I found difficult was judging small nuanced changes in the dark density of the negative. Perhaps it really doesn't matter and the timing either way is not that critical. However, based on nearly 40 years experience with time/temp development I'm hard pressed to think that being off >10% on the development time wouldn't affect the final outcome? I think the viewing light has a lot to do with proper judgement of a completed negative. I followed MAS's recommendation of a green safelight with 15-watt bulb at least 4 feet away from the development tray. The negative is judged via glancing light from the base side for a couple secs. Again, I found judging proper density through that milky looking negative difficult. I watch a YouTube video of a guy demonstrating DBI and he placed the viewing light directly in front of his tray such that when he lifted the negative up for viewing he was looking at it through transmitted light; and his negative looked to be about 30cm from the light! I may try that someday....
     
  17. David M

    David M Well-Known Member Registered User

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    Alan,
    I'm sure that your direct experience is worth far more than my third-party anecdotes. Presumably the method works well for some people.
    I wonder about your 10% remark. Clearly, it will make a difference, but surely we've all printed from negatives that were less than perfect? There seems to be a school of thought (not on this forum) that only a neg with Z1 placed exactly at 0.01 above FB+F is worth making. I hesitate to quote the Sacred Works of AA, but both Moonrise and Frozen Lake and Cliffs are made from inadequate negatives. I have another third-party memory of a professional printer commenting on how poor the quality of negatives was that he got from "some famous" photographers. No further details in my memory, alas.
    As before, I bow to any first-hand experience you may have.
     
  18. Alan9940

    Alan9940 Active Member Registered User

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    Hi David M,
    Totally agree with everything you said. Do I make "perfect" negatives every time? Absolutely...NOT! My 10% remark was more "tongue in cheek" to emphasize my point. I guess my thinking is that I want to be kind to the guy in the darkroom. ;) If I can consistently produce negatives that print easily, then why not? The mole in the dark (me!) will surely appreciate it! :D
     
  19. David M

    David M Well-Known Member Registered User

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    Moles of the World unite. Nothing to lose but a bin full of frustration.
    I can remember staying up all night and using a whole box of 20x16 paper, trying to get that print exactly right. Next day, the house was full of damp paper. When I came to mount the final, really, absolutely perfect one, I couldn't tell which one it was. Then I came across someone who tore a tiny corner off The One...
     
  20. Alan9940

    Alan9940 Active Member Registered User

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    Great story...thanks! Reminds me of a print I worked on years ago. It was nothing particularly special; a farm scene with cows in a field and beautiful puffy white clouds. What attracted me most to the scene was the "glow" of the sunlight raking across the landscape. Took me near a full 100-sheet box of paper, different developer formulas and additives, and many hours of effort, and I felt I had achieved my goal. Best compliment I ever received was when I showed it to a fellow workshop participant and he said, "Oh my, light seems to emanate from the paper."
     

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