KODAK WRATTEN -V- B+W: TMax 100

Discussion in 'B&W: Film, Paper, Chemistry' started by Bruce Osgood, Feb 15, 2008.

  1. Bruce Osgood

    Bruce Osgood Membership Council Council

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    I working with 4X5 TMax 100 now and noticed in the Kodak Publication F4016 the reference to KODAK WRATTEN Filter factoring and exposure. I have B+W filters.

    How do the Wratten Factors compare to the B+W X factor? I cannot find any reference to Wratten at the Schneider site.

    An example:
    My B+W Red filter is B+W #90. It has an exposure factor (X) of 5 which means to open the shutter 2,5 stops. As I understand it.

    The Wratten No. 25 (red) simply says open 3 stops.

    For TMax 100 opening the lens for the B+W #90 3 stops is not the answer... I can prove it.

    Thanks for for your thoughts,
     
  2. John Koehrer

    John Koehrer Subscriber

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    If you still have the data sheet from B+W it should have the Wratten equivalent on it. Well,at least their old ones had it.
    Regarding the exposure factors, as they say YMMV.
     
  3. Jim Noel

    Jim Noel Member

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    The difference in color sensitivity of the T-Max films and conventional grained films, may cause a difference in the factor for some colors of filters.
     
  4. DWThomas

    DWThomas Subscriber

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    There's some potentially useful info here.

    I agree with Jim Noel that spectral curves of specific films play a role in the results with filters.

    DaveT