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  1. #1
    Photo Engineer's Avatar
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    Why I use Photo Flo 200

    The attached pictures show why! I am taking HRSTs advice!

    Kodak had patented an addendum that increases speed and contrast of a given emulsion. The pictures below show examples of an AgBr emulsion with 3% Iodide and a Sulfur finish that compare surfactant X and Photo Flo 200 used as surfactant.

    The results show that there is an ingredient in Photo Flo that is covered in that patent (well, I knew that ) ! The results are about 1/2 stop in speed and about 1/2 grade of contrast. These two photos were identically exposed and processed.

    This does NOT work with several other emulsions that I tried, but it does work with this one on a repeatable basis. There are several other compounds that do the same. I hope to report on them as well.

    PE
    Attached Thumbnails Attached Thumbnails AgBr Enlarging paper without PF.jpg   AgBr Enlarging paper with PF.jpg  

  2. #2
    hrst's Avatar
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    Thanks! Interesting. Was the surfactant added just before coating? How can it cause an increase in speed like this? And why is this compound in Photo Flo 200 in the first place?

  3. #3
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    It is added as a normal surfactant just before coating. It is used at the normal level. If it is not, then coating defects result.

    IDK why it causes the effect. It is a development accelerator though, and that is all that I know. I was directed to the patent by a friend after I observed the effect. It can be attributed to either Poly alcohols and / or poly ethers. I have no more information at this time, but hope to get some at the end of the month at our next GEH lunch.

    See what happens when I take advice? More work for me!

    PE

  4. #4

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    PE,
    Isn't Photo Flo 200 diluted Triton X200? I remember looking at the structure of the latter ( in Sigma-Aldrich, I think). It has 1 sulfur atom. Perhaps this is a source for acceleration. Just a thought from a rank amateur.
    Bill

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    I have use Photo Flo 200, like it very much!

    Jeff

  6. #6
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    Photo Flo 200 contains Triton X 100 plus several other ingredients. It contains no Sulfur atoms.

    PE

  7. #7
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    That is really neat. Thanks for this and all your other posts.

    Regards
    Richard

    Why are there no speaker jacks on a stereo camera?

  8. #8
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    So what are we saying here? That the use of photoflo increases the apparent film speed after the fact? Or is just an emulsion coating related property?
    Stop worrying about grain, resolution, sharpness, and everything else that doesn't have a damn thing to do with substance.

    http://www.flickr.com/kediwah

  9. #9
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    An emulsion coating property AFAIK. If it works after the fact, that is a bonus!

    PE

  10. #10

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    This is interesting! I've got to coat some glass soon, so I'd like to give this a try. how are you applying the photoflow to the glass?

    I'll take a guess. Clean the glass, the submerge in photoflow (mixed to the right dilution) then let dry before coating?

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