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  1. #21
    hrst's Avatar
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    Thanks!!

    How I "measured" the "about ISO 10":

    I adjusted the enlarger light to approximate sunlight (added some cyan+magenta) so the comparison would be "fair".

    Then I exposed my step wedge film (I have made it before on BW film) to Agfapan APX100 at a specific exposure and processed in XTOL 1+2 for 3 mins.

    Then I opened lens three stops and exposed my film and processed it in the same way.

    After processing, I noticed that the lowest density wedges on my film and APX100 match quite closely. And, because I opened lens three stops, it's ISO 12,5. Very precise .

  2. #22

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    Hrst,

    Great results! Thanks for posting your process and results, keep up the experiments. Inspiring!

    Emulsion

  3. #23
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    First real image!

    This emulsion is fantastic!!

    We took a real photo at ISO 10. Indoors, it was 2 seconds at f/2! We made a print on Kentmere multigrade paper. It prints nicely on normal contrast. Print looks very good. The attached scan is not so good (scanner is something like 15 years old).

    Developing is much more fun than with normal films, because the emulsion loosens from the base. You have to be very careful!

    This image was originally 35 mm image! Still the grain is not bad at all! But our process has a super cool INTERPOLATION system (just like DIGITAL ZOOM but analog!): emulsion stretches during processing and a 35 mm frame ends up almost as a 645 frame .

    OH YEAH!
    Attached Thumbnails Attached Thumbnails ohyeah!!!.jpg  

  4. #24
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    Very nice, congratulations.

    Is this the sulfur sensitized version? You could now add Erythrosine to make an Ortho sensitive version. This would probably gain you a little camera speed due to the added sensitivity.

    Best wishes.

    PE

  5. #25
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    Thank you.

    This is the most sulfur sensitized version of the three, but they all gave the same results in step wedge test so this is same ISO10 as the unsensitized one. Heat treatment after adding the hypo was insufficient.

    Next, hardening (and better base, or a subbing layer). Then, better sulphur sensitization and erythrosine. Then we may start experimenting with chlorophyll to try to make a panchromatic film! We have a BW video camera (IR sensitive), IR leds and a small monitor. Not quite the same as IR goggles but better than in completely dark.

  6. #26
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    Erythrosine

    I've read here that erythrosine has to be added in a specific way to make it work properly. Can you give some hints how (and how much) to add it and how this differs from the addition of other kind of dyes?

  7. #27
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    I cannot due to the differences between your emulsion and mine.

    I would suggest about 50 mg of erythrosine / mole of silver, added as a 1% solution in water. That is a good starting point.

    PE

  8. #28
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    Our coating blade

    Version 0.01

    Attached Thumbnails Attached Thumbnails blade_a.jpg   blade_b.jpg  

  9. #29
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    They look very nice and quite similar to my film and plate coating blades.

    PE

  10. #30

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    Great job with the results!
    Kirk

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



 

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