Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,872   Posts: 1,520,117   Online: 861
      
Page 1 of 6 123456 LastLast
Results 1 to 10 of 53
  1. #1

    Join Date
    Jan 2011
    Shooter
    Multi Format
    Posts
    84

    Making separation negatives using RA-4 material?

    OK, maybe I am reinventing the wheel, maybe this issue has been previously discussed at length (IDK), so I apologize in advance if this is the case.
    And maybe it would be better to post this contribution to Chris' dye transfer post.....
    But anyway:

    I was thinking how nice it would work if one would separately expose a slide with all 3 colors on 3 sheets of RA4 material (possibly transparent), like Kodak Endura transparency, or some Ilfocolor transparent material. (just to check, ordinary RA4 paper would be perfect).
    Then, you develop those exposed sheets in some ordinary BW developer (with no chromogenic activity) to get the desired contrast. Then you fix in your ordinary BW fixer and you get a BW negative image derived from one color only. PLUS, you can work with a dim 590nm light, not in total darkness (as you should with a panchromatic material).
    Then you would get 3 negatives ready to be printed onto your gum-bichromate, carbon, DCG or any other material requiring contact printing with a UV source.
    That would be the "analog route" to big negatives, doable in an average darkroom, without some expensive hardware (you don't even need an inkjet). And probably, any RA4 material is reasonably priced (since it is a mass product)

    what do you think, fellows?

  2. #2
    Curt's Avatar
    Join Date
    Sep 2005
    Location
    Pacific Northwest
    Shooter
    Multi Format
    Posts
    4,531
    Images
    15
    I have no idea but keep investigating it.

  3. #3
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,907
    Images
    65
    Why not use LF sheet film then? That would work. The transparent Endura is really a bit translucent. It is intended for poster ads.

    PE

  4. #4

    Join Date
    Jul 2011
    Shooter
    8x10 Format
    Posts
    2,461
    I'd be concerned about the linearity, ability to boost and balance contrast to suitable DMax, and cost. But if you want to try it, what the heck?

  5. #5

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    I have used Kodak Duraclear RA-4 clear film for this very Thing, I have 3 huge 24x24 multi-layered separation prints made like this. Today, Duraclear is digitaly exposed using tri-color lasers, but still developed via RA-4. Cofusingley, Duraclear is transparent. Duratrans is translucent. It will still work using an enlarger.
    Bill

  6. #6

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    T-Grain,
    You just gave me an idea. Like 4 simultanius,and very different, projects are not enough for me. Today's digital negatives employ not only density, but color(hue) for optimum absorbtion/reflection for a given process. There are several methods published for generating curves for optimum digital negatives. It occured to me that the same thing could be done with an analog (RA-4) processed transparent color film. An expensive way for making negatives! But why not?
    Bill

  7. #7
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,907
    Images
    65
    These curves with masking and C/M/Y/K images were used in the printing industry for years.

    PE

  8. #8

    Join Date
    Apr 2005
    Location
    San Bernardino, CA
    Shooter
    8x10 Format
    Posts
    734
    Yes P.E.
    I' m realy good at reinventing the wheel. But then, the wheel has been reinvented thousands of times. Try puting wooden wagon wheels on a BMW.
    Bill

  9. #9
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,907
    Images
    65
    Bill;

    I've done that myself at EK a few times!

    PE

  10. #10

    Join Date
    Jan 2011
    Shooter
    Multi Format
    Posts
    84
    thanks, guys! looks like something interesting is developing out of this post (pun intended)
    PE, even if Endura is translucent-this is probably the back of the material, probably not an issue, or the same (not to the same extent) as when using paper negatives? isn't sheet film a bit more expensive than RA4 material? that's why I came to the idea of using it.....
    Bill, thanks for the info, and I am glad that I am not the only "reinventor of the wheel"

Page 1 of 6 123456 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin