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  1. #11

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    Quote Originally Posted by nworth
    D-23 does pretty well. Strangely enough, it has very pronounced acutance behavior and is semi-compensating. The main complaint is its high sulfite content. If you are unhappy with the results of using it straight, try it at 1:3 (with about double the developing time).
    If you want a true acutance developer that is Metol based try Neofin Blau or the Beutler formula posted in the APUG Chemical Recipes.

    Quote Originally Posted by nworth
    Most any of the acutance developers you would use for 35mm will perform the same way with 8X10. That opens up a whole pile of packaged products. You are not so concerned with grain at 8X10, so one of the staining developers could be very good. Try PMK of Pyrocat-HD.
    PMK contains Pyrogallol, and Pyrocat-HD contains Catechol and D-76, ID-11, DK-50 and HC-110 all contain Hydroquinone, so they are all presumably unacceptable to the originator of this thread.
    Tom Hoskinson
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  2. #12

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    Tom, I'm a little confused... pyrogallol and pyrocatechol were the chemicals I was refering to when I said non-pyro. Hydroquinone was not. Am I missing something?

    Thanks
    bob

  3. #13

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    Quote Originally Posted by Keith Tapscott.
    Acutance tends to be much more noticeable with 35mm rather than larger formats, by the time you get to 6x9 medium format, any differences are hardly noticeable at all. Grain is hardly a problem when enlarging 4x5 negatives and none at all when contact printing, especially a 10x8 negative, the most important thing is to get the exposure and development right.
    Developers such as D-76, ID11, Xtol, DK-50, Rodinal etc should prove to be entirely satisfactory.
    I don't agree with this. IMO the advantages of a high acutance developer are even more important with LF and ULF than with 35mm and medium format. With 35mm and medium format one usually magnifies the image in projection printing, which enhances the existing adjacency effects. Only so much is allowable, however, and at some point grain and loss of tonal values becomes objectionable.

    With LF and ULF, assuming the same film, developer and type of agitation, you will get the same level of .effects, but they will not transfer into as much apparent sharpness in a contact print because they are not enhanced in magnification..

    So with LF and ULF I think it best to chose a developer and type of agitation that maximizes acutance, since grain and loss of tonal qualities will rarely, if ever, become a major problem with film of size. Essentially one can get away with much more exaggerated effects since they won’t be magnified in enlargment.



    Sandy

  4. #14

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    Quote Originally Posted by bobbysandstrom
    Tom, I'm a little confused... pyrogallol and pyrocatechol were the chemicals I was refering to when I said non-pyro. Hydroquinone was not. Am I missing something?

    Thanks
    bob
    Bob,

    What Tom means is that pyrogallol, pyrocatechol and hydroquinone are all in the same family of developers, and there is not of lot of difference in toxicity between them. So if your purpose in rejecting pyro developers is based on concerns about toxicity, logic suggests that you would also want to reject developers that contain hydroquinone, which include many common ones.

    Or maybe you could just use catechol and not call it a pyro developer! Would Pyrocat-HD still be a pyro developer if I changed the name to CATCH-22?

    Sandy

  5. #15

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    Quote Originally Posted by bobbysandstrom
    Tom, I'm a little confused... pyrogallol and pyrocatechol were the chemicals I was refering to when I said non-pyro. Hydroquinone was not. Am I missing something?

    Thanks
    bob
    Yes,

    Hydroquinone is a benzine ring chemical which differs from pyrocatechol only in the position of the OH on the benzine ring. In low sulfite developers, it proportionally stains and tans the emulsion. Its human toxicity level is similar to that of pyrocatechol.

    Pyrogallol, Pyrocatechol and Hydroquinone are most toxic to humans as dry chemicals - inhaled or ingested (this is also true of Metol, Glycin, PPD, Amidol, etc).

    In solution at working dilutions they are not really a health problem, unless you expose your skin or mucous membranes to them or drink them.

    When weighing and mixing dry chemicals do it under a hood or use a proper filter mask/respirator.

    Use nitrile gloves (I use SafeSkins) when handling wet chemistry. This precaution should be taken with most (if not all) developing chemistry.
    Tom Hoskinson
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  6. #16
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    Accutance developer .... humph! - An accutance developer builds ridges on light and dark borders. You can have a sharp photo without much accutance but high accutance will appear much sharpter. High accutance developers usually make the grain bigger. D-23 and MicrodolX erode the grain and have so much sulphite in them that they reduce sharpness for smoother tonality (which makes them low accutance). Most pyro developers increase sharpness by tanning the emulsion which allows greater activity at the edges. D-76 1:1 is pretty good at disolving and then re-depositing silver at the edges - but 76 full strength doesn't. XTOL has sulphite and does have decent accutance but I wouldn't say it is an accutance developer. Ascorbic Acid and Phenidone both tend to reduce accutance unless there is other chemistry that conpensates. I like 510 Pyro but it doesn't have near the accutance generation of P'cat. I have not seen triethonalamine developers - PC-TEA or 510 Pyro increase accutance alothough they make a sharp image, edge effects are not enhanced. And I have used all these developers quite a bit. For good usable accutance - I would place my money on P'cat but for non pyro: I'd stick with D-76(d) 1:1 D-76(h) is simpler and easier to homebrew - (no hydroquinone) or better would be Mytol - an XTOL homebrew using mostly vitamin C and a tiny bit of Phenidone and some ph buffers.
    My photos are always without all that distracting color ...

  7. #17

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    Quote Originally Posted by Tom Hoskinson

    Pyrogallol, Pyrocatechol and Hydroquinone are most toxic to humans as dry chemicals - inhaled or ingested (this is also true of Metol, Glycin, PPD, Amidol, etc).

    In solution at working dilutions they are not really a health problem, unless you expose your skin or mucous membranes to them or drink them.
    Hydroquinone solutions are not regarded as dangerous by contact. Millions of people have used skin creams with hydroquinone in concentrations around a few percent, comparable to very strong developer. They are regarded as safe by dermatologists for use up to three months.

  8. #18
    Ole
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    Quote Originally Posted by sanking
    ...
    So with LF and ULF I think it best to chose a developer and type of agitation that maximizes acutance, since grain and loss of tonal qualities will rarely, if ever, become a major problem with film of size. Essentially one can get away with much more exaggerated effects since they won’t be magnified in enlargment.
    ...
    I beg to differ. Since sharpness and grain do not change to any significant degree with developing (still speaking LF and ULF here, where enlargement is typically small to none), I would place the main emphasis on tonality. Loss of tonal qualities is the only important thing to avoid. So find the developer and agitation pattern that gives the tonality you want, and forget about acutance and grain! The acutance, by your own argument, is irrelevant "since they won't be magnified in enlargement."
    -- Ole Tjugen, Luddite Elitist
    Norway

  9. #19

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    Quote Originally Posted by Ole
    I beg to differ. Since sharpness and grain do not change to any significant degree with developing (still speaking LF and ULF here, where enlargement is typically small to none), I would place the main emphasis on tonality. Loss of tonal qualities is the only important thing to avoid. So find the developer and agitation pattern that gives the tonality you want, and forget about acutance and grain! The acutance, by your own argument, is irrelevant "since they won't be magnified in enlargement."

    But your premise is incorrect because sharpness and grain do change in developing. That is why many people have switched to minimal types of agitaiton with LF and ULF to produce very enhanced adjacency effects. This also increases grain size somewhat but the effects are not significant with LF and ULF film.

    Obvioulsy you don't want to lose tonal qualities, but that is not going to happen with LF and ULF film so long as the macro contrast of the negative is normal. I suppose it is possible that the exaggerated edge effects could become so great at some point that they might interefer with tonal qualities, but this is not very unlikely to be seen with LF and ULF film because the effects are not enhanced by magnification.

    You are free to agree or not with my observation, but I know for a fact that in my own work I see greater apparent sharpness in contact prints that are made from negatives developed with minimal and extreme minimal agitation than from negatives developed with continuous agitation, as in rotary processing. And that is assumes that the negatives are developed to the same macro contrast. And in fact, before the thread was hijacked, that is exactly the point that people like Steve Sherman were making in the recent thread on stand development.


    Sandy

  10. #20
    Ole
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    Quote Originally Posted by sanking
    ...
    Obvioulsy you don't want to lose tonal qualities, but that is not going to happen with LF and ULF film so long as the macro contrast of the negative is normal.

    You are free to agree or not, but I know for a fact that in my own work I see greater apparent sharpness in contact prints that are made from negatives developed with minimal and extreme minimal agitation than from negatives developed with continuous agitation, as in rotary processing, even when using the same developer and dilution and when macro contrast is the same.

    Sandy
    In my experience the macro contrast is not related to tonality, instead tonality is something which "lives" between macro- and microcontrast. For lack of a better term I think of it as mesocontrast. Think of this as contrast over a range of up to a few mm - more than edge effects, yet too small to correct by burning & dodging.
    The greater apparent sharpness with minimal and extreme minimal agitation are due partly to an increase in mesocontrast as a consequence of the longer development needed to get the same macrocontrast as with continuous or "normal intermittent" agitation.

    I have seen the same effects, and in many cases find that it damages the "smoothness" I want. In other cases it is better, I won't argue against that.

    But my point is (or has become by now) that the agitation pattern is more important for the tonality than the type of developer. Still I have some favorite developers that I use when I have specific wants for tonality - like Efke 25 and 50 in Neofin Blau (or Beutler's).
    -- Ole Tjugen, Luddite Elitist
    Norway

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