reducing negs

Discussion in 'B&W: Film, Paper, Chemistry' started by kwit, May 15, 2014.

  1. kwit

    kwit Member

    May 15, 2014
    i have ten 4x5 black and white tri-x negs
    that were over exposed (not over developed) a few stops
    the subject matter was an outdoor snow scene on an overcast day last winter
    so the negatives have more highlight density areas than shadow detail areas
    but both are equally important
    i need to reduce the over exposure density equally
    but i do not need to reduce the contrast
    anybody have any experience with these photographers formulary products ?
    reducer for negatives 2
    reducer for negatives 3
    i'm not sure which to use in this situation
    and would appreciate feedback
    from anybody with experience using both products
    thanks for your help
  2. Rudeofus

    Rudeofus Subscriber

    Aug 13, 2009
    Medium Format
    From what I have read, reducers are a trial and error thing, so you would not want to use them on valuable negatives before you fully understand what they will likely do to them.

    Are you 100% sure that these negs are so dense that you can't print through them? It's not like a 4x5 negative needs all that much enlargement ...
  3. Thomas Bertilsson

    Thomas Bertilsson Member

    Jan 21, 2003
    Multi Format
    Replicate the 'problem' with a couple more 4x5 Tri-X negatives and work with them before you start working on the actual negatives.

    The risk you run is that the bleach will affect the shadow tones more than you want it to, while having a less profound effect on the denser highlights. That would mean an increase in contrast, which is what you are not wanting to achieve.

    That's why it's a good idea to do some testing before taking a nose dive into it.
  4. michael_r

    michael_r Subscriber

    Feb 2, 2010
    Montreal, Canada
    Multi Format
    I'd suggest first trying to print the negative as-is, because reduction is not a highly controlled process. It requires trial/error, and image structure characteristics may or may not be affected.

    If you decide to try reduction, what you are looking for is often termed a "cutting" or "subtractive" reducer in the literature. This is one that removes the same amount of density everywhere, used to correct for overexposure with a minimal effect on contrast. However getting true cutting action without some amount of proportionate action can be difficult.

    Single solution Farmer's/Kodak R4a (which I believe Formulary sells as Reducer 1) is probably the best bet for a subtractive reducer. But there are variables which may result in it acting more like a proportional vs subtractive reducer. One variable is the film itself (apparently the wider the size distribution of silver particles, the more the reducer will tend towards proportional rather than subtractive reduction). A second set of variables are the concentrations and also the proportions of Ferricyanide to Thiosulfate in the solution, which can have an influence on whether the solution acts subtractively or proportionately. Depending on the film, tweaking the concentrations and proportions may or may not help. Experimentation would be required.

    However it might not be worth worrying about as much as all that. Some degree of proportional action may be an acceptable compromise if you end up with the less dense negative you are after. You lose a little contrast, but this can be corrected in printing.

    As noted by others, since the process can be tricky to control and unpredictable, practice/experiment on scrap negatives first.