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  1. #31
    keithwms's Avatar
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    So, one advantage I can see to reconstructing the goo is that it'd be quite easy to design a roller system that would apply it very sparingly, evenly, and reproducibly. Goo obviates the uneven wetting issues with watery liquids. The goo could be pre-applied like a condiment to the rollers from a little packet like you get at McDonalds.

    ...and then there is simply shooting to paper...

    P.S. Ron that formula looks totally trivial, could it really be so?! Now where is my aldrich catalogue when I need it...

    SIMON! How about making some magic goo for us, in little condiment packs?
    "Only dead fish follow the stream"

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  2. #32
    David A. Goldfarb's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    The gel acts as a surfactant to spread the developer evenly and also as a 'glue' to hold the two parts together for a short time.

    PE
    Yes, but I was thinking it might be interesting to try it as a liquid just to see how it develops film.

    hmmm... if it's a liquid rather than a gel, I suppose the reaction times will be different, so it may need to be rebalanced.

    That's quite a lot of sodium hydroxide, isn't it? FX6a uses 10g/l, and this uses 50g/l.
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  3. #33
    Steve Smith's Avatar
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    Quote Originally Posted by keithwms View Post
    CC, if you aren't familiar with Land's story, his biography by McElheny would be a very interesting read.
    I can second that. It goes into quite a bit of detail on the black and white process (I can just about follow it!). As for colour...... You would need to be some sort of Photo Engineer to understand that!

    A very good book which I recommend to anyone with an interest in the technicalities of photography.


    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  4. #34
    Photo Engineer's Avatar
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    Quote Originally Posted by David A. Goldfarb View Post
    Yes, but I was thinking it might be interesting to try it as a liquid just to see how it develops film.

    hmmm... if it's a liquid rather than a gel, I suppose the reaction times will be different, so it may need to be rebalanced.

    That's quite a lot of sodium hydroxide, isn't it? FX6a uses 10g/l, and this uses 50g/l.

    I was merely indicating that it would work without the CMC as that has only thickening proprties in the goo. The alkali was near 1 molar. Thats about 40 g/l for NaOH.

    But, there are other ingredients and I have forgotten them over the years.

    PE

  5. #35
    keithwms's Avatar
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    Well, if it's of any service, I can do Raman, IR, Uv-vis-NIR and NMR on the goo and figure out what's in it....

    But surely polaroid would be willing to provide us the formula if we file a class-action lawsuit claiming severe emotional distress...
    "Only dead fish follow the stream"

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  6. #36
    Photo Engineer's Avatar
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    Actually, you also need some sort of rail arrangement to insure the correct gap. If you take a sheet of any Polaroid material apart, you will see a paper or cardboard cutout of the image area in which the goo is spread. This acts as a separator with the correct gap (rails) to spread the goo correctly.

    Keith;

    At this point what I need is an SEM to study my emulsions. Got one? Can you do carbon replica? Can you remove gelatin?

    PE

  7. #37
    keithwms's Avatar
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    Well, I was trying to think of a way to make use of all those pola processors and backs.... seems like making a proper goo spreader won't be hard.

    Ron, yes, I do have SEM. TEM too!

    By carbon replica, do you mean sputter with gold and image that? If so then yes, that's easy, I do that with nanotubes all the time.

    Gelatin I can remove for sure with fuming nitric :o

    What about AFM? Why muck with SEM on low-Z materials? I have AFM in my group. Come down and play. Jack M. would love to hear about it if he were still around.
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  8. #38
    Photo Engineer's Avatar
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    Well, Keith, gold treatment will work as well. The emulsion images I posted were either EMs or SEMs. The EMs were carbon replicas and the SEMs were carbon + gold IIRC. The silver halide was removed as was the gelatin.

    I'm not sure about AFM, as it does not give me the information I need IIRC. Neither does TEM.

    I need size and frequency in the 0.1 - 10 micron range.

    PE

  9. #39
    keithwms's Avatar
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    My AFM does 100 micron scans with lateral res ~10nm, height res ~1nm. You get size and frequency. I guess you plan to use NIH Image or similar to build a frequency/size histos. IIRC I have some particle analysis software that I never used.

    Oh incidentally I can do 100x100 micron Raman maps, if that is of interest. Might be because there is surface enhancement you get from silver grains.

    Anyway, SEM is easy enough.
    "Only dead fish follow the stream"

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  10. #40
    Photo Engineer's Avatar
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    Keith;

    Not interested in Raman, sorry. I think that since my stuff is all EM or SEM, comparison might be difficult with other formats. I don't kneed height resolution as I am not making t-grains (yet). Can you give me a cost estimate?

    PE

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