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  1. #1

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    Fomapan 100 classic anti-halo effectiveness

    Hi,
    I'm starting this topic derived from my last one about reversing Fomapan 100 classic.
    How's effective the anti-halo of Foamapan 100 classic?
    I'm getting glowing highlights with some unusual halo around very bright objects, where there's a sudden change from white to black.
    The pre-wash water remains clear.

  2. #2

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    http://www.fotoimpex.de/shop/images/...(Englisch).pdf
    Fomapan 100 classic has NO anti-halation backing!

  3. #3
    Ian Grant's Avatar
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    You need to re-read that PDF where Foma mention the Anti-halation backing at the bottom right of the first page.

    I've used a lot of Fomapan 100 and never had a halation issue.

    Ian

  4. #4
    AgX
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    The AH-layer is only mentioned with reference to type 120 and sheet film, not with reference to 35mm.

    Foma meanwhile got a new data-sheet with a different text referring to the bases and AH-layers, but still not with reference to 35mm.

    Typically 35mm film has not got an anti-curling backlayer, which often contains an anti-halo function. But in this case the AH-layer could be placed on top of the substratum under the emulsion. The optimum location anyway.
    Last edited by AgX; 12-27-2012 at 09:30 AM. Click to view previous post history.

  5. #5

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    Quote Originally Posted by Ian Grant View Post
    You need to re-read that PDF where Foma mention the Anti-halation backing at the bottom right of the first page.

    I've used a lot of Fomapan 100 and never had a halation issue.

    Ian
    Hi Ian,
    there's no mention of a anti-halo backing for 35mm.

    "The following bases are used for manufacturing the particular sorts of the film:
    - 120 rollfilm - a bluish polyester base 0.1 mm thick, furnished with a matted colour backing which will decolourize during processing. The backing has anti-halation and anti-curling properties and prevents the incidence of Newton rings during
    enlarging.
    - 35 mm film - a gray or gray-blue cellulose triacetate base 0.125 mm thick,
    - sheet film - a clear polyester base 0.175 mm thick furnished with a matted colour backing which will decolourize during processing. The backing has anti-halation and anti-curling properties and prevents the incidence of Newton rings during enlarging.
    "

    There's no mention of a anti-halation backing for 35mm...

  6. #6
    Ian Grant's Avatar
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    The 35mm section has a comma at the end and so the comments for the anti-halation backing etc are the same as for sheet film.

    The effects you're describing are probably over developerd and blown out high-lights. Foma films need careful testing to find the right exposure index and development time, they are rather prone to excessve contrast and over development if you aren't careful and need about 2/3 to 3/4 th development time of other films.

    Ian

  7. #7
    AgX
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    Quote Originally Posted by Ian Grant View Post
    The 35mm section has a comma at the end and so the comments for the anti-halation backing etc are the same as for sheet film.
    I thought so too. But in this case it would be a bad lay-out or wording. See above for my added hint for another location of the AH-layer.

  8. #8

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    Or could be a typo: a comma instead of a period...
    However it's rather difficult to overdevelop when reversing, and I've done preliminar tests to find that Fomapan 100 classic reverses bets when exposed @160 and first developed for 12min (that's the standard time for first development).
    Does overdevelopment in a reversal context controls only Dmax, while Dmin is only controlled by exposure (that is the exact contrary of a negative)?
    Could this glowing effect be the reason why Dr5.com says that Fomapan 100 classic cannot run in his process?
    Last edited by Alessandro Serrao; 12-27-2012 at 09:58 AM. Click to view previous post history.

  9. #9
    Thomas Bertilsson's Avatar
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    As I understand it, Foma 35mm film does not have effective anti-halation coating. I've noticed this in both ISO 200 and ISO 400 versions of the film. It's really beautiful for portraiture for this very reason. I haven't shot a lot of the ISO 100 film in 35mm, mostly in 120, where the same the 'blooming' around light/dark boundaries is not as visible.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  10. #10

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    It would be interesting to ask Foma directly but they don't answer any email.

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