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  1. #11

    Join Date
    Mar 2003
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    Greenville, SC
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    Quote Originally Posted by ciocc
    I just printed my first Pd/Pt prints last weekend using Tmax 100 negatives. The negatives were made using the repackaged Tmax 100 with the new developing times. The film was developed in D-76 using the standard procedure, no tricks. I exposed the negative to the sun for 1.5 minutes after having made a test strip with a maximum time of 18 minutes. The sun was just about directly overhead on a cloudless day. The print looked great to me, but to be sure, I showed it to my neighbor who is an experienced Pt/Pd printer. He said the print was fine, not underexposed. He was surprised by the 1.5 minute exposure time. The 21 step tablet placed next to the negative had 13 distinct steps - sometimes it looks like 12 when the viewing light is different.

    I don't know why I'm not having the UV problem described. Would using the sun have anything to do with it? Obviously I'm not disappointed, but it's strange that I'm not having the problem.
    The fact that you are exposing with the sun may indeed be the reason the UV base is not having any impact on your exposures. The UV blocking of TMAX-100 is in a fairly narrow range of the UV wavelength while Pt./Pd. is sensitive to light from well outside this range. The sun provides radiations in a very wide band on both sides of the UV filter and this could well explain why it is more efficient in printing Pt./Pd. than the artifical lights we normally use in exposing this process, which emit light in a fairly narrow band of wavelength.

    On the other hand, direct sun puts out a lot more radiation than most artifical light sources so the reason for your short exposures could the power of the light source.

    Sandy
    Last edited by sanking; 04-19-2005 at 10:21 PM. Click to view previous post history.

  2. #12

    Join Date
    Sep 2004
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    Boston, MA
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    Quote Originally Posted by sanking
    The UV blocking of TMAX-100 is in a fairly narrow range of the UV wavelength while Pt./Pd. is sensitive to light from well outside this range. The sun provides radiations in a very wide band on both sides of the UV filter and this could well explain why it is more efficient in printing Pt./Pd. than the artifical lights we normally use in exposing this process, which emit light in a fairly narrow band of wavelength.
    Sandy
    If someone has a sample of the "old" and the "new," then I could run a test of the UV transmittance of both and post the results. It would be best to use developed and fixed, but not exposed, film. If that is not possible, then I could work from the typical negs that folks have created during normal use. The test is non-destructive and of course I would exercise all due care, but I would rather not have someone's latter day equivalent of Moonrise! Please PM me if you have examples of both the original and the "UV blocking" film.

    Best, jk

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