TMY-2 in XTOL Contrast Anomaly

Discussion in 'B&W: Film, Paper, Chemistry' started by Denis K, Aug 16, 2009.

  1. Denis K

    Denis K Member

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    On this bright sunny day in Baltimore, I was setting out on the balcony in my apartment reading a March 2008 copy of the Kodak XTOL data sheet; thinking how nice it would be to be in the darkroom developing some film. I was looking at the 400TMY developing times in the small tank developing time table on page 6, when I noticed that the stated times for EI 400 and 800 are identical, with the only difference being that Kodak claims that you will get a higher contrast index (CI) at 800 (0.62 vs. 0.56). This seems counter intuitive to me. Granted, many people claim to get higher contrast with TMY-2 by exposing at an EI of 800, but I have always thought these folks have been extending their development time accordingly. Now, here is Kodak claiming that adjusting development time isn't necessary. Now I could see getting higher local contrast with some film/developer combinations by underexposing them, but my reading of the sensitometry curves for TMY-2 in XTOL are such that doing that would give lower local contrast, not higher local contrast. Furthermore, by underexposing film and not extending development time I can't see how you could possibly expect to get higher ISO contrast. FWIW, my understanding is that this data sheet has been updated for the new and improved TMY-2, which is the film I'm specifically interested in. Most of the other films do not have this apparent anomaly.

    Does anybody have any explanation for this?

    Ref: http://www.kodak.com/global/en/professional/support/techPubs/j109/j109.pdf

    Denis K
     
  2. Ronald Moravec

    Ronald Moravec Member

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    Kodak also does this for all tab grain films. You WILL lose one stop of shadow detail. Move development will not get it back either.
     
  3. Denis K

    Denis K Member

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    Ronald, I could see this if the D-Log-E curve rolls over in the highlights, but what I'm seeing in XTOL is an upswept curve with a bit more contrast in the highlights and a bit less in the shadows. Thus if one pushes the scene brightness down the curve, with no additional development time, shouldn't one expect to give up the higher contrast portion of the film curve? With the high exposure range of this film, that may be what you have to do to get some true blacks, but I wouldn't call that a higher contrast index.

    This truly looks like an interesting film/developer combination.

    Denis K