unexposed Film identification

Discussion in 'Film and Processing' started by terence_spross|1, Jul 7, 2006.

  1. I have a couple rolls of bulk film and the labels are no longer legible, they
    could be color or they could be B&W. (This is in the color negative catagory as
    there is no general film catagory.) I also have a few single rolls of 35mm that
    are identified, and it seems I have an old roll in a processing tank - never
    processed. So it occured to me that a chart would be usefull to many people as a
    reference.

    Does anyone know of a reference of unprocessed film identification based on
    apperance of film front and back, sproket hole cut, and overall thickness that
    could help identify unknown films and segregeate them. A method of detecting if
    the base is triacetate or polyester would also be useful. Mine could be Ilford,
    Kodak, B&W negative, color negative, or E6 transparency film. Due to the rem-jet
    backing I can identify old Eastman 5247 film as that is the only soluble backing
    film I ever purchased.

    I've searched for such a chart elsewhere and the only thing if found is notch
    identificataion for sheet film and identifacation of processed film.

    The goal of all this may be to compile a complete chart based on responces here
    and in other forums (on my website when I create it), therefore since I intend
    to give credit where credit is due, please mention your sources if you can give
    me any clues. I expect this to take some time to collect complete info and I can
    start by measureing films I know that I have in my posession.
     
  2. Terence, color film is easily diffentiated from B&W by the appearance of the base, but the best thing to do is a 'snip test'. You can roll off a section into a cassette and ask a processor to develop (not print) it and then examine the edge markings.

    If you have B&W processing at home, you can develop it in that chemistry and possibly (not always) develop out a distinguishable edge marking be it B&W or color negative.
     
  3. There was a time when I could distinguish many kinds of film by the color of the raw stock, but I'm out of practice. There are a couple things that are likely to work:

    Most B&W film is unhardened so if you put a small piece in hot water (100F) and rub it, the emulsion will fall off. Most color film manufactured in the last 25 years is hardened and will not fall off.

    If you scratch the emulsion of color film, you will be able to see different layers that are different in color. A B&W film will be more uniform.
     

Share This Page