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  1. #1
    Ray Bidegain's Avatar
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    100 TMAX the base and UV process

    Did I miss something about the new 100 tmax having a base that blocks UV?

    Ray Bidegain

  2. #2

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    Quote Originally Posted by Ray Bidegain
    Did I miss something about the new 100 tmax having a base that blocks UV?

    Ray Bidegain
    Yes you did, apparently Kodak has incorporated a UV coating and the film is no longer useful for alt printing.

  3. #3

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    Quote Originally Posted by Ray Bidegain
    Did I miss something about the new 100 tmax having a base that blocks UV?

    Ray Bidegain
    The fact that the new Tmax 100 has a base coating that blocks UV light to the tune of about log 1.0 has been discussed on several lists. That is more than three stops of density, which means a three stop increase in exposure times for UV sensitive processes. That changes a basic two minute exposure into one of 32 minutes.

  4. #4
    Ray Bidegain's Avatar
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    Well that explains it.

    Thanks,

    Ray Bidegain

  5. #5
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    I ran into trouble the other day helping someone do Van Dyke Brownprints for the first time. His exposures were well beyond what normally should have produced a good print with a negative falling within the recommended density range for VDB. At that point I noticed the 4x5 negative had a textual film code for "TMAX 100" next to the notch code and I realized this must be the new TMAX 100 film. He brought the box in today and sure enough, it was the new flavor of TMX.

    I then ran an exposure test using a Nu-Arc 26-1K mercury plate burner. My normal exposure for double-coated VDB on Cranes Kid Finish and an HP5+ negative is around 400 units of exposure. I gave the this test 500 units which took 29 minutes.

    For the test I attached a Stouffer wedge to a sheet of new TMAX 100, another to a sheet of old TMAX 400, and another test wedge in direct contact with the paper (i.e., no film in the UV path) in the middle of the test image. The visible FB-F as measured on a transmission densitometer was 0.02 for both films, neither of which had been developed, only fixed and cleared.

    My results indicate the new film is blocking 4 steps or ~2 stops exposure at this level of 500 units total exposure. To compensate for this, the 500 unit exposure would need to be extended to 2000 units and that would take nearly 2 hours to expose.

    If interested you can view the test image at:
    http://my.net-link.net/~jsmigiel/ima...l/VDB_TMAX.jpg

    Bye bye TMAX.

  6. #6

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    Quote Originally Posted by smieglitz
    My results indicate the new film is blocking 4 steps or ~2 stops exposure at this level of 500 units total exposure. To compensate for this, the 500 unit exposure would need to be extended to 2000 units and that would take nearly 2 hours to expose.

    If interested you can view the test image at:
    http://my.net-link.net/~jsmigiel/ima...l/VDB_TMAX.jpg

    Bye bye TMAX.
    On another forum it was reported that the UV coating can be removed by soaking in an alcohol solution, after processing is completed. I have not tried the soak myself but several people report that it works.

    Sandy

  7. #7
    bmac's Avatar
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    am I the only one that finds this totally insane? Does Kodak R&D even use the products they market? I doubt the UV would be an issue on roll film, but for Sheet film, C'mon folks!
    hi!

  8. #8
    smieglitz's Avatar
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    Quote Originally Posted by sanking
    On another forum it was reported that the UV coating can be removed by soaking in an alcohol solution, after processing is completed. I have not tried the soak myself but several people report that it works.

    Sandy

    Sandy,

    Do you recall which alcohol was used? Are we talking methanol, ethanol, or hopefully isopropyl ?

    Do you have the link to the thread on the other forum?

    Thanks,

    Joe

  9. #9
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    Quote Originally Posted by smieglitz
    Sandy,

    Do you recall which alcohol was used? Are we talking methanol, ethanol, or hopefully isopropyl ?

    Do you have the link to the thread on the other forum?

    Thanks,

    Joe
    Hi Joe,

    Go here for more info:

    http://largeformatphotography.info/l...ic/499758.html

    Don Bryant

  10. #10

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    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.

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