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  1. #11
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    There is a UV filter layer. It is often in the topmost layer but sometimes between the red and green.

    PE

  2. #12
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    Ok, thanks for correction! I thought there wasn't one since it's always stressed that you must have an UV filter in your light path after the bulb.

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    Ok, so given that there's one there, and I had one in my filter pack aswell, could it have been some IR response in the paper that caused the red channel to look like that ?

    Also, returning to the original question Is it more magenta/yellow filtration required do you think ?

  4. #14
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    Quote Originally Posted by hrst View Post
    Ok, thanks for correction! I thought there wasn't one since it's always stressed that you must have an UV filter in your light path after the bulb.
    For color printing, it is a Heat Absorber / IR filter that is needed as well as a Wratten 2B.

    Color paper does have a slight sensitivity to near IR. The UV sensitivity is high due to use of Chloride in the emulsions. The UV filter is there mainly for dye stability.

    Therefore, both are needed.

    PE

  5. #15

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    Ah ok, so that probably accounts for that. Doing a quick search seems to indicate that actually blocking IR might prove troublesome (or expensive ...). Something like a hoya HA-30 looks as though it could go some way toward solving the issue though ?

  6. #16

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    Quote Originally Posted by hrst View Post
    No there's no IR sensitivity at all, but as PE said earlier, it's very sensitive to UV.
    Actually it seems from the datasheet that the cyan-forming layer sensitivity peaks at 700nm, so there is just a little IR sensitivity there.

    Edit: Ooops, PE beat me to it!

  7. #17

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    So an 85C, strong UV filter such as B+W 415 and a CC filter (orange?) should do for filtration in daylight? Has anyone - OP, perhaps - tried the latest Kodak Endura Premier or even Fuji Fujiflex polyester material for in-camera RA-4 and reversal processing?

  8. #18

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    Guess I should bite the bullet, buy a roll of Fujiflex, experiment with it and post the results here...

  9. #19

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    Ah, I have been pondering on the same subject for the days. I might try filtering it with a glass slate I pulled out of a 35mm projector lamphouse, supposedly blocks UV and IR and is coated greenish on one side and purplish on the other. And if it was good enough to tame a 6kW lamp then it should be good enough for this.

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