View Full Version : Newton Rings?

Robert Ruderman
26-Oct-2005, 08:16

I am using a Saunders LPL enlarger to print my 4x5 b&w negatives.

I am using a Saunders glass negative carrier which, according to the packaging, has anti-Newton ring glass on the top adnd regular glass on the bottom.

Many of my prints still show evidence of "wood ring" patterns in them, which I am guessing are Newton rings. These rings are patterned like what you might see on a 2x4 piece of milled lumber around a knot-hole.

1) Is this what a Newton ring looks like?
2) Any suggestions as to what can/should be done to eliminate the rings? They vary in size and location from photo to photo and are quite a distraction.


Oren Grad
26-Oct-2005, 08:53
Robert - Yes, that sounds like Newton's rings. What film are you using? I have the LPL 4x5 enlarger with glass carrier as well. It works fine with every film I've tried except for T-Max 100, which is so smooth on the emulsion side that occasionally I will get Newton's rings.

Frank Doering
26-Oct-2005, 10:17
Robert, I had the same problem with the same outfit. It's worse with smoother emulsions (e.g. TMX), and terrible when you use sandwiches (e.g. unsharp masks) because of increased pressure. I had a Florida outfit called "Focal Point" replace the bottom glass in my carrier with Anti-Newton [ring] glass. That solved the problem. Careful comparisons showed no sign whatsoever of print degradation even at 15x magnification. You could also try Tetenal Anti-Newton Spray.

Oren Grad
26-Oct-2005, 10:30
What I've done is to replace the bottom glass in an LPL glass sandwich carrier with a piece of Denglas, which is an anti-reflection coated glass normally sold though professional framing shops to provide glare-free viewing of framed artworks.

It's expensive as glass goes, but a small piece like 4x5" won't be prohibitive. You do have to find a shop that's willing to let you sort through a few pieces to find one that's really clean because Denglas is prone to small surface defects that are not important for framing purposes but do matter for this application.

Robert Ruderman
26-Oct-2005, 11:23
Oren & Frank - Thanks for the responses. I am using TMAX-100 film. I actually had to go to a glass carrier because I found that the heat rendered by the enlarger was causing the negative to buckle during exposure. Using the glass carrier fixed the problem but has now introduced the Newton Rings.

It sounds like you two went through the effort to replace the bottom glass (non anti-Newton glass from what the literature says) and I guess I'll follow suit.


Pat Kearns
26-Oct-2005, 11:38
Robert, have you tried dividing your exposure time by 1/2, 1/3, or 1/4 and then give the paper the exposure time x 2, 3, or 4 with a cool down period between each exposure? I print with glassless carriers and if I have long exposure times I usually try this method to prevent buckling.

Tom Westbrook
26-Oct-2005, 12:58
One solution I found to this was to put strips of tape over the stainless bars holding the glass in. Progressively build up tape until the glass no longer puts pressure on the film. FWIW, I use 1/4" black 3m photo tape for that. Also, see largeformatphotography.info/lfforum/topic/500921.html#539698 (http://largeformatphotography.info/lfforum/topic/500921.html#539698) for an additional idea. Following the treatment indicated, I had to add the tape as the shim removal didn't quite do the trick for me.

ronald moravec
26-Oct-2005, 14:35
Normally AN glass only goes on top. Make sure it is in the top half and not upside down so the AN surface is to the outside. Strange things happen! Lightly pass a razor knife over the surface. An AN surface will sound a little rough. LIGHTY I said. Do not scratch it.

Rings form between the base and glass, normally not emulsion and glass.

If you have a glassless carrier, try using the bottom of the glassless with the top from the glass.

Glass is not required on the bottom as heat makes the film bow up.

Let`s hear what you find.