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Thread: flashing paper

  1. #1
    New Orleans, LA
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    flashing paper

    In an effort to take grade 3 Lodima paper down a half or, ideally, a full grade I am looking for techniques that would do this and came across this on the Adox Lupex data sheet:

    LUPEX comes in the universal grade 3. The grade can be reduced by pre-exposing the paper. In order to do this the paper is exposed under the lightbulb for a few seconds* before the negative is placed on top and the "real“ exposure takes place. * The optimal pre exposure has to be found by tests. It is usually between 5 and 15 seconds.

    Anyone use this technique to their satisfaction? Used in conjunction with water bath development? I'm going to give it a try and report back.

  2. #2

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    Re: flashing paper

    Thom,

    Yes, exposing the paper to non-image forming light (ie flashing) reduces contrast. What you want to do in your case is give the paper the maximum exposure which does not produce any visible tone. This will require a few tests.

    Flashing reduces contrast most in the highlights and progressively less as paper density increases.

    Michael

  3. #3
    Steve Sherman's Avatar
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    Re: flashing paper

    A trick that worked very nicely with AZO and Amidol developer would be to start with a grade higher contrast than you want. Reduced the development time in Amidol
    Developer for as short as 10 seconds and then remove
    to an ordinary plan tray of water and continue to agitate the print till a total of 1 minute has elapsed. You may have to give slightly more base exposure but the benefit is a reduced overall contrast while still preserving a sense of the Mid Tone relationship of the higher contrast paper.
    You can increase the time in Amodol to create a very specfic paper grade and look


    Real photographs are born wet !

    www.PowerOfProcessTips.com

  4. #4

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    Re: flashing paper

    There are a lot of things you can do to reduce contrast of a graded paper.

    Flashing is one of them, and works primarily in the highlights, as mentioned. I use is rarely to tame highlights such as a sunlit scene outside a window in a dark room that I'm photographing.

    Developing for a shorter time (snatching the print when it looks right) works too, mainly in the shadows. This is more like developing film, which rarely gets developed to d-max. A more dilute developer together with increased exposure helps here.

    I can get a grade less contrast just by using a soft-working developer like Selectol Soft, Ansco 120 or ID-3 (recipes are easy to find). If you normally use a standard higher-contrast developer, such as Dektol, this will get you about a grade less contrast. If you're using an amidol developer and don't want to change, then this won't help.

    I've used water-bath development, like David describes above, with some success as well. It may work better for chloride papers and amidol than for other scenarios.

    You can also use SLIMT techniques to control contrast. This involves a bleaching of the print in very dilute potassium ferricyanide/potassium bromide bleach after exposure and before development. This needs a lot of testing but offers a lot of control. Search for the articles by David Kachel for detailed information.

    Best,

    Doremus

  5. #5
    bob carnie's Avatar
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    Re: flashing paper

    I find flashing helpful when printing street images, the flash will sensitize the paper so that I can print at a higher grade to get my contrast needs done, and when I want to bring in highlight detail I drop to a lower filter to burn the bright lifeless areas and the image basically pops into view without resorting to ridiculous burn times.

  6. #6
    Louie Powell's Avatar
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    Re: flashing paper

    David Vestal called it 'The Art of Darkroom Photography' for a reason - there are many techniques that can be used to fine tune the final contrast in a print. Flashing is one of them. Flashing can be applied either before or after the base exposure although the results may be slightly different.

    In classic flashing, you first remove the negative from the carrier, and then close the lens aperture to reduce the light that is then flashed onto the print. This is a big hassle. An alternate trick is to use a flashing card. A flashing card is simply a sheet of cardboard with a large, rectangular hole in the middle, and a layer of thin (relatively translucent) drawing paper (which is probably hard to find these days) glued over the hole. With a flashing card, you leave the negative in the carrier and you don't change the aperture - but you do move the card during the flashing exposure just in case the drawing paper has a texture that you don't want transferred to the print. The length of the flashing exposure is the one remaining variable.

    Obviously, dodging and burning are options, as well as bleaching, rubbing highlights with your finger to cause friction that raises the local temperature and increase localized developer action, water bath development, diluted developers, etc. If you go back to some of the older books, you can read about penciling (using a pencil to carefully add a thin layer of charcoal to increase negative density), or dye-dodging where a tinted dye is applied to the back of the negative to increase local density. These techniques are especially useful with sheet film.

    But as David would have noted - these are all experimental techniques. Experienced darkroom workers understand them can use them effectively, but each use involves some degree of trial and error, and it is necessary to keep careful notes if you want to be able to repeat the technique and get similar results in the future.

  7. #7
    Rick Olson's Avatar
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    Re: flashing paper

    Reopening this thread ... I have been using Adox Lupex silver chloride paper for contact printing and have been able to adjust the contrast through use of green and blue gels. This recommendation was from a post that Steve Sherman made in the past and I have been using it since (Thanks Steve!). In my process, I am able to get what I feel is about 0.5-1.0 grade more contrast with the blue gel and 1 to 2 grades less contrast with the green. The green is most dramatic in affecting the contrast.

  8. #8

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    Re: flashing paper

    Really! Lupex is somewhat variable contrast? Sounds like a great tool for contact printers!

  9. #9
    Rick Olson's Avatar
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    Re: flashing paper

    Hi Doremus ... yes, great getting multiple grades from Adox Lupex. The gels did not affect contrast with Ilford Galerie or Bromportrait, two other papers I use for contact printing.

  10. #10

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    Re: flashing paper

    Hi Rick

    this is very interesting!

    I recently put in my first box of Lupex paper and worked with an old contact print device. Exposure time of approx. 12 sec. I am very satisfied with the color tone and the fineness / resolution, but the prints are too high-contrast. Is it really possible to influence the contrast with the Rosco Supergel 389?
    Do you have any examples?

    I didn't find any advice on this at Adox. Only preflashing is mentioned ...

    regards
    NormaN

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