Anti-newton ring strategy - 35mm

Discussion in 'Enlarging' started by michael_r, Sep 28, 2010.

  1. michael_r

    michael_r Subscriber

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    I've found I only really need a top glass to maintain good flatness. Having experimented with regular glass with thin spacers, anti-newton ring glass etc, I would now like to try using the glass from a multicoated clear B+W filter (not a UV filter, just a clear protective filter). I'm wondering if this might be an interesting alternative if the multicoating helps cut down on the interference effect. I have a spare filter so figured I'd pop the glass out of the ring and use it in the negative carrier on top of the negative.

    Anyone have any thoughts on this? In theory should the anti-reflective multicoating reduce the newton ring effect? Or not?

    Thank you.
     
  2. tomalophicon

    tomalophicon Member

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    What was wrong with the anti newton's ring glass?
     
  3. Bob-D659

    Bob-D659 Member

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    Interference patterns will not be affected by coated glass. They will look different if the glass you are comparing it to is not a polished optical flat as is the filter. The only guaranteed way to a flat neg and no newton rings is a wet mount, messy but it works super well.
     
  4. richard ide

    richard ide Member

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    The newton rings are a light interference pattern between 2 smooth surfaces and the vaying thickness of the air film between them. Anti-newton glass and other methods of eliminating them such as using starch prevent the 2 surfaces from coming into close contact the way they do with regular glass. Google newton ring theory for a better explanation
     
  5. Vlad Soare

    Vlad Soare Member

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    Back when I was using an enlarger with glass negative carriers, I removed the bottom glass altogether and replaced the top one with the glass from an anti-newton 35mm slide mount. Problem solved.
    Curiously, I've never got any Newton rings with medium format film. Only with 35mm.

    My current enlarger uses glassless negative carriers. I'll never go back to glass.
     
    Last edited by a moderator: Sep 29, 2010
  6. michael_r

    michael_r Subscriber

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    Thanks everyone for the responses. For 35mm I have both glassless and glass carriers (top glass only) with various types of glass. Trying different things.

    To answer tomalophicon, I've never had reliable success with anti-newton ring glass. First, I sometimes get newton rings anyway. Second, depending on the image, the texture on the glass is sometimes visible in the print.

    One day I'd like to try wet mounting. It seems like a real mess and I'm not quite sure how you get the negative clean after.
     
  7. Doremus Scudder

    Doremus Scudder Member

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    Vlad, you and I are the heretics!

    I agree, ditch the glass. You'll have less dust, more time and no Newton's rings.

    I got glass carriers because of all the hype about greater sharpness and just found them to be a PITA. Plus, they didn't deliver sharper results than I was getting already. Maybe if I were enlarging my 4x5 negs to larger than 20x24 I would find them necessary. As it is, I need a loupe to resolve all the detail on the prints. That's sharp enough for me.

    The reason for glass is to keep the negatives flat. There are other ways to do this. With your 35mm negs, a good carrier should hold them very flat.

    Best,

    Doremus Scudder
    www.DoremusScudder.com
     
  8. michael_r

    michael_r Subscriber

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    It is not heresy. I use glassless carriers fairly often but for negatives requiring lots of burning, popping is sometimes an issue. Refocusing after the negative pops doesn't really work unless I stop way down. As for dust, I've never found that to be as much of a problem with glass carriers as people suggest. I just keep everything very clean and give a final blast of compressed air on all surfaces right before closing the carrier. I've never had a problem (besides the damn newton rings, although it happens less often in the winter months when humidity is down).
     
  9. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    Yes glass carriers are PITA. You have 6 surfaces to keep dust free. When there's humidity, there's Newton's rings, when the air is dry, there's static electricity which attracts dust. There's no winning using them.
     
  10. michael_r

    michael_r Subscriber

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    Only 4 surfaces for me with 35mm. I only use glass on top.
     
  11. darkosaric

    darkosaric Subscriber

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    You can cry to put on top, or between glasses cardboard with of size of hole little bigger than negative (example - cardboard size of 4x5 cm, hole size 26x38mm), that will hold negative tight to bottom glass. I did this on magnifax 3, no newton rings at all.
     
    Last edited by a moderator: Sep 29, 2010
  12. perkeleellinen

    perkeleellinen Member

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    35mm is a pain for me also but curiously only Kodak negs, I have no problem at all with Fuji. AN glass makes no difference. I've been experimenting with something similar to what darkosaric, above, suggests. I make a thin shim just a little thicker than the neg which I then place next to the neg between the glass inserts, this seems to be enough to relieve the pressure between the neg and the carrier but still enough to grip the neg and hold it flat. I probably need to print a bit more before I'm confident this is a solution and I can start buying Kodak films again.