Pre-Exposure Material

Discussion in 'B&W: Film, Paper, Chemistry' started by djklmnop, Dec 5, 2004.

  1. djklmnop

    djklmnop Member

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    Quick question for all. I've been finding more and more reason to use pre-exposure. But I can't find the right material for it? Do you guys use a single sheet of paper and the lens set to infinity? Or do you have a dedicated white painted-over pexiglass?

    Any ideas?

    Andy
     
    Last edited by a moderator: Dec 6, 2004
  2. wildbill

    wildbill Member

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    White plexiglass or Lexan.
     
  3. Leon

    Leon Member

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    I use two sheets of greaseproof baking parchment held in a lee gelsnap filter holder. Works fine.
     
  4. ann

    ann Subscriber

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    well, i am not one of the guys, but i use white plexi
     
  5. rogueish

    rogueish Member

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    OK
    What is pre-exposure and why would one (guy or gal) want to do/use it?
     
  6. ann

    ann Subscriber

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    it is a technique used to raise the expsoure value of a low zone. You place the "filter" in this case white plexi over the lens and expose a piece of film usually zone I to Zone II. Then following with a normal exposure without the "filter". It is an option used sometimes with subjects that have a high contrast range and one does not want to pull the development .

    Check Ansel Adams writings for more detailed information.

    Most commonly used with sheet film, but can be used with roll film, if the camera will allow making a double exposure.



    In the old days, it was very common for press photograhpers to expose sheet film on clear days. they would just shoot the sky and then put the holder away for a time when the lighting conditions were very dim and use the pre-exposed film which of course added density to the negative, but no detail, helping the printing with thin negatives.
     
  7. rogueish

    rogueish Member

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    ahh. That makes good sense, Thanks!
    All the little things, tips and tricks, are what make this site so great!
     
  8. hortense

    hortense Member

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    I use plastic foam coffe cup.