Colour negs more prone to Newton's Rings?

Discussion in 'Color: Film, Paper, and Chemistry' started by perkeleellinen, Nov 4, 2009.

  1. perkeleellinen

    perkeleellinen Member

    Messages:
    2,258
    Joined:
    Apr 14, 2008
    Location:
    Warwickshire
    Shooter:
    35mm
    I've been printing B&W for the best part of a decade and have never had a problem with Newton's rings. I assumed I had anti-Newton glass in my neg carrier. I've just started colour printing and I'm getting loads of rings from a roll of Ektar.

    So, are colour negs more prone to Newton's Rings?

    Flat bed scan then digi P&S: there's at least 5 rings on this print.

    [​IMG]
    [​IMG]

    Apologies for the colour balance, it's a test print that the digi systems have taken to 'correct' (wrongly).
     
  2. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,034
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Never found colour films to be any worse, but I stopped using glass for the top with 35mm and use a plain mask in my Dursts, that way I just don't get newtons rings and I found it better for dust control too.

    Ian
     
  3. perkeleellinen

    perkeleellinen Member

    Messages:
    2,258
    Joined:
    Apr 14, 2008
    Location:
    Warwickshire
    Shooter:
    35mm
    I could try that. Presumably your negs are sufficiently flat using this method.
     
  4. Tom Kershaw

    Tom Kershaw Subscriber

    Messages:
    2,948
    Joined:
    Jun 5, 2004
    Location:
    South Norfol
    Shooter:
    Multi Format
    I've recently printed Kodak Ektar 100 and Portra negatives with glass negative carriers and suffered Newton Rings. Using the same carrier with ILFORD Delta negatives produces no Newton Rings.

    Tom
     
  5. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,034
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Just as flat as with Glass on top. I made my own mask back in 1975 when I was a penniless student, Durst wanted too much for a simple piece of painted aluminium :D

    Ian
     
  6. Anon Ymous

    Anon Ymous Member

    Messages:
    1,480
    Joined:
    Feb 7, 2008
    Location:
    Greece
    Shooter:
    35mm
    Perkeleellinen, I use a glassless negative carrier for my Opemus 6a and enlarge from 135 negs only. I don't know about larger negatives, but I never had a problem with flatness. I use a 75W bulb, so the generated heat is not that much to cause problems either. A 150W bulb might cause problems, but I don't know. As an added bonus (as Ian said) you only need to clean dust from the negatives, not the carrier.
     
  7. perkeleellinen

    perkeleellinen Member

    Messages:
    2,258
    Joined:
    Apr 14, 2008
    Location:
    Warwickshire
    Shooter:
    35mm
    Anon - I also have the Opemus 6a and enlarge only 135. Good to know you've had no issues with a glassless carrier. My current carrier is the metal one with adjustable masks. I've got a glassless insert somewhere around here (which I filed out in my youth!). Later today I'll try to replace the top glass with that.
     
  8. AgX

    AgX Member

    Messages:
    11,917
    Joined:
    Apr 5, 2007
    Location:
    Germany
    Shooter:
    Multi Format
    Using matting agents in a back layer is described in literature, however a hint at this I found so far only in two data sheets:

    …back layer of the film (designed to achieve optimum vacuum draw down)…

    Back layer designed for best reduction of Newton rings.


    respectively


    (To avoid confusion: a back layer does not necessarily need to be based on gelatine or a swelling polymer it can also be made of a waterinsoluble polymer, a lacquer.)
     
    Last edited by a moderator: Nov 4, 2009