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Thread: A real formula

  1. #81
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    An old style variant of this is in Baker 2nd Edition as a high speed emulsion. You may wish to look at that. However, none of these old texts really say how much Ammonia, and sometimes not even what kind (in modern terms). Baker used Degrees Baume for his Ammonia designation and you have to convert to percent. A real pain.

    PE

  2. #82

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    You can use lookup tables like from the middle of your CRC Handbook of Chemistry and Physics to figure out the Baume to percent conversion.

    Or search the web...
    http://www.hillbrothers.com/ammonia/...operties-1.pdf
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  3. #83
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    Kirk, this can be done but there somewhere you will find a discontinuity in the way Baume was reported and you have to interpolate. At least that is what I remember. I had some problems and just finally guesstimted 28% because the values given in the BIOS and FIAT reports were at the high end of the charts. Which is 28% in terms of concentration.

    And, BTW, just as British and US gallons differ, IIRC German and British/US degrees Baume differ.

    PE

  4. #84
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    I hope this isn't a red herring, but the owner of one of the better camera shops here told me last week that silver mines all around the world are closing down because of the shrinking film market. He said film had been one of the main uses for silver for decades.
    Any truth in this? And for those interested in making their own formulae, what sort of stockpiles are there for silver nitrate?

  5. #85
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    Actually, due to the economy, some say that silver demand is up as governments and individuals try to buy enough silver for coins or to buy silver coins. Which is true? IDK.

    PE

  6. #86
    MDR
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    Les its very doubtful that Film manufacturing is the reason for closing the mines, it's more likely that some investors or funds are closing the mines to create a short supply and a rise in silver price.

    Another thing just found this site selling ballistic gelatine http://www.gelatininnovations.com/pa...fications.html would that be active gelatine, they specifically state that it's not food gelatine.

    Dominik

  7. #87
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    I have no idea myself.

    PE

  8. #88
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    Quote Originally Posted by MDR View Post
    would that be active gelatine
    If you want active gel, just buy food grade sheets from the supermarket. I have had great results with that and it clearly is active and did the sulfur sensitization just as expected with this formula without extra steps.... Plus, you will get the same great uncertainty as in the old days .

  9. #89
    MDR
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    Thank you for the responses, hrst since you're from Finland what Gelatine Brand are you using?

    Dominik
    Last edited by MDR; 12-18-2011 at 08:31 AM. Click to view previous post history.

  10. #90
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    The brand and batch # will probably make some difference in the results with unrefined gelatin.

    PE

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