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  1. #31
    Shawn Dougherty's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Gerald - I think there was a thread on this once in which PE validated the desensitization effect. It was in the context of BTZS tubes and how they are supposed to work without total darkness even though you have to keep removing the top to pour in chemicals.
    Thanks, Michael, I'll have to dig up that thread. When spinning my homemade BTZS style tubes I use a small red safelight behind me when I take off the lids and transfer the then uncapped tubes into a tray of fixer. I've done it with and without the safelight and can see no difference whatsoever...

  2. #32

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    I did a brief search on people who have used a desensitizer. One user with pinakryptol yellow said it allowed the safelight (with a 15w bulb) to be on continuously and at a distance of 2 feet without fogging.
    Last edited by Gerald C Koch; 02-07-2014 at 01:42 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  3. #33

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    Quote Originally Posted by Shawn Dougherty View Post
    That's right, they do use ABC pyro. I watched Paula develop film this way and I've dabbled in it myself. Never noticed any fogging that seemed different than what I'm used to... by eye anyway. I've never measured it with a densitometer. My understanding is that there is only a SLIGHT increase if done properly.

    I'm just curious about what is actually happening. I would LOVE to get some nice IR googles, glass trays with an IR light source underneath them some day.

    i use the green light often
    with caffenol-130
    i mean sumatranol-c-130
    works like a charm

  4. #34

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    Quote Originally Posted by Gerald C Koch View Post
    I did a brief search on people who have used a desensitizer. One user with pinakryptol yellow said it allowed the safelight (with a 15w bulb) to be on continuously and at a distance of 2 feet without fogging.
    Right, but these kinds of compounds are usually intended for desensitization. I was referring to varying degrees of desensitization as a side effect of the normal development process. I thought maybe I had read about it in Haist or one of the other books but I'd have to go back and check.

    Also, apologies to everyone - I found the BTZS thread I was thinking of (turns out I started that thread! ) but re-reading it now there is nothing really in there about desensitization from PE or anyone else. Memory failure due to old age. I've deleted my previous post on this.

  5. #35

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    Quote Originally Posted by Gerald C Koch View Post
    The problem with evaluating the negative based on the emulsion side is that you are seeing reflected light only. So you are seeing only the surface of the emulsion, the rest of the emulsion may be undeveloped. Stopping development at this point will lead to thin negatives. This is why the base side is used since if you see a satisfactory image it means that the entire emulsion has been developed. Thus the warning to inspect the base side of the film. Every discussion of the technique that I have read always mentions doing this.

    The idea that the oxidation products of the developer act as a desensitizer is very old. If the effect ever existed it would be dependent on the developing agent(s) used. I seriously doubt that the developing agents used now would have the same effect. The oxidation products of phenolic developing agents like pyrogallol are vastly different from those of a developer like Xtol.
    Gerald, does that mean you are supposed to use transmitted light from the base side? I have been looking at the base side with reflected light. Is that wrong?
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

    Regards
    Bill

  6. #36
    cliveh's Avatar
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    When Gerald mentioned this, I thought how can you view other than reflected light from both sides until cleared with fix.

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  7. #37
    Bill Burk's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    I'll also throw in my white elephant for the fun of it: why anyone would bother in this day and age with DBI versus time/temperature control is beyond me.
    My favorite DBI negative is the indoor swimming pool at Hearst Castle... I KNEW it was going to be a thin neg when I shot it. When I saw it in the tray, still thin after the prescribed time, I kept it in as long as I possibly could... about 4 more minutes till my wife said we absolutely positively HAD to go. Otherwise I would have left it in longer. Can't remember the occasion. The negative still is a bit thin for my taste, but makes a beautiful dark print.

  8. #38

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    Quote Originally Posted by cowanw View Post
    Gerald, does that mean you are supposed to use transmitted light from the base side? I have been looking at the base side with reflected light. Is that wrong?
    No, the emulsion is opaque so you must use reflected light. But to see if development is near completion you have to look at the base side.

    Development by inspection does not work very well if the film or its base contain a lot of dyes. So the newer t-grain films are a problem.

    Let me say this again: for most people and for most situations the time/temperature method of development is much easier and more accurate. Development by inspection requires a good deal of experience to get it right. I know that it has a certain mystique for some people but that in itself is not a sufficient reason to use it. I used it many years ago when light meters were an uncommon luxury. I would have preferred not to.
    Last edited by Gerald C Koch; 02-07-2014 at 10:43 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  9. #39
    Sirius Glass's Avatar
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    Quote Originally Posted by Bill Burk View Post
    When I saw it in the tray, still thin after the prescribed time, I kept it in as long as I possibly could... about 4 more minutes till my wife said we absolutely positively HAD to go.
    Lessons Learned when I was still a child "Never stand in the way of a man [or woman] on the way to the bathroom."
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  10. #40
    Mainecoonmaniac's Avatar
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    I'm not good at it. But I'd imagine it's like cooking. Some recipes recommend a cook time, then finish the dish by looking at the doneness. Finishing the dish by eye. But before then, you don't have to peek. I would only inspect the film's highlights the last few minutes of the development cycle.
    "Photography, like surfing, is an infinite process, a constantly evolving exploration of life."
    Aaron Chang

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