B&W Contrast grades to Filtration Numbers

Discussion in 'Enlarging' started by PhotoBob, Apr 19, 2006.

  1. PhotoBob

    PhotoBob Subscriber

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    Hi:
    Does anyone have the colour combination numbers that correspond to the paper grades for the Bessler Dichro 45 computer colour head enlarger?
    Thank you
     
  2. Marco Gilardetti

    Marco Gilardetti Member

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    Beseler, you mean? And for which brand/type of paper?
     
  3. Ronald Moravec

    Ronald Moravec Member

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    Every pack of Ilford Multigrade has instructions and filter conversions.

    Until you get the proper info, 30 cc magenta will get #3, 60 cc #4 etc. Yellow is about the same. You will need to increase exposure or use different combinations that add a lot of neutral density to maintain even exposures.
     
  4. Pragmatist

    Pragmatist Member

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    Here are the equivalencies. Both filter arrangements lead to the same contrast grades, however the double filter system is intended to keep the exposure time and aperature the same across contrast grade changes.

    MULTIGRADE EQUIVALENCIES FOR ILFORD RC
    GRADE__SINGLE__DUAL
    00_____200Y____200Y/0M (162)
    0_______90Y_____90Y/0M
    ½_______70Y____78Y/5M
    1_______50Y____68Y/10M
    1 ½_____30Y____49Y/23M
    2________0_____41Y/32M
    2 ½_____5M_____32Y/42M
    3______25M_____23Y/56M
    3 ½____50M_____15Y/75M
    4______80M______6Y/102M
    4 ½___140M______0Y/140M (150)
    5_____200M______0Y/200M
     
    Last edited by a moderator: Apr 19, 2006
  5. PhotoBob

    PhotoBob Subscriber

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    Thank you all for the information.:smile: