Can someone put this in film terms

Discussion in 'Pinhole Photography' started by mark, Apr 8, 2005.

  1. mark

    mark Member

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    From the MGIVRC data sheet


    The speed of MULTIGRADE IV RC depends on the
    filtration used during exposure. MULTIGRADE IV
    RC unfiltered, has a paper speed of ISO P500.
     
  2. Ornello

    Ornello Inactive

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    ISO paper speeds have no direct relation to film speeds.
     
  3. Bob F.

    Bob F. Member

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    Just as there is an ISO standard for film speeds, there is also an ISO standard for paper speeds. Just don't ask me what that standard is (!) - no doubt it will be defined on the Web somewhere... ISO is the International Standards Organization.

    Cheers, Bob.
     
  4. mark

    mark Member

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    Thanks Jay and Bob.
     
  5. Christopher Colley

    Christopher Colley Member

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    I meter my MGIV at ISO 6 and have acceptable results without any filtration. on a pinhole with an fstop around f/345, focal length of 100mm on a 'sunny 16' exposure its normally around 1minute 30seconds.

    When putting a filter on it, I dont recall the exact numbers but I believe 0 - 3 all have a paper ISO around 200, and 4-5 are 100. Without a filter as mentioned its 500. Using these measures you can adjust your exposure accordingly, a #5 contrast filter puts the paper at 100 'iso' and a #2 puts it at 200 'iso' ..... at least in my experience doubling and halfing exposure has seemed to work just as it does with film ISO..
     
  6. mark

    mark Member

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    Thanks Christopher.