Cursed by Newton Rings

[Dr Croubie]

So I've got an LPL6700 6x7 colour diffusion head, and it came with only a 24x36 glassless carrier.
Given that I shoot 24x18, 24x36, 645, 6x6, and 6x7, I thought it best to get the Universal Carrier with 4-blade adjustment and whatnot. So as to not get Newton Rings (I thought), I also got the ANR Top Glass.
Problem is, it's just not that simple, I'm still getting Newton Rings, I can only presume from the bottom glass. So far from 6x7 Ektar and 24x36 TMX, I haven't tested any others yet.

I did give 'wet mounting' a go, using Lumina Scanning Fluid, but just couldn't get rid of the air bubbles (maybe it could work if I cut the individual neg and used mylar/tap like I do with scanning, but that'd only work on 24x36, there's not enough room to get sticky tape outside a 6x7 area).

Anyone else got any magic fixes for Newton Rings?
Trying to get the neg off the bottom glass I suppose is the goal, maybe cutting out a paper mask so top->bottom is ANR->neg->paper->plain glass might work? (Kind of makes having a nice 4-bladed neg carrier rather redundant though).

 

[Oren Grad]

I have an LPL 4500II with its universal glass carrier - AN on the top, plain glass on the bottom. I can't speak to color neg, but among B&W silver films, TMX is the only one that gives me problems - the emulsion side is that smooth. No problem, ever, with TX, HP5 Plus, Delta 100, or any other film that has a clearly visible texture to the emulsion side.

I agree, getting the emulsion side off the glass is probably the way to go. I haven't fussed with it yet myself, as I use very little TMX. But I too would be interested to hear of anyone else's experience in working around this.

 

[polyglot]

Odd. I used to have one of those enlargers with the glass carrier and it did not do newtons rings. As an experiment, have you tried a less-glossy film? I suspect you may be having rings from reflections off the emulsion because both Ektar and TMX are very very shiny. Try some Ilford, they tend to have a more-papery feel and my guess is would be less prone to newtons rings.

 

[Hilo]

I assume the glossy side of your negatives faces up? I think the only way the bottom glass can cause Newton rings, is if one places the negative glossy side down.

I use the Leitz Focomat 2C for 120 film and I never have these problems. The top glass in the carrier is AN. Sometimes (not often) I want to print without the AN glass and replace it by a clear glass. For that occasion I have cut some masks from black carton. These have the same size as the glass plates, and I cut out in the middle a little larger than 6X6 and 6X7 (I often include the black borders in the print). So, the negative is in the same position as always, the matte side facing down. Then the carton goes on the glossy side of the negative, then the carrier closes with the clear glass pressing the carton onto the negative strip.

You can simply do this to check where the Newton rings come from. You could even test with cut-out carton on both sides. I am not saying this is ideal for all your future printing. It will just show you where your problem is caused.

In the end I think your AN glass is not working and you should consider to have it replaced. Wet mounting sounds terrible to me.

 

[polyglot]

I assume the glossy side of your negatives faces up? I think the only way the bottom glass can cause Newton rings, is if one places the negative glossy side down.

Some films are very glossy on the emulsion side too. I have an old scanner that will produce newtons rings if you put TMX, Acros or some colour films in it.

 

[Dr Croubie]

Yep, looks like my curse might have been to print the two glossiest films around
At least I haven't shot too much TMX in 120, I've got a lot of TMX and TMY (and a bucket of TX) in 135 but I can probably go glassless for that. Most of my 120 is Ilford, thankfully (both developed and in the freezer), so if they're all good then that's a bonus.
I just hate to think in a few years (decades) when I can afford to turn my spare room into a real darkroom and have space for an 8x10 enlarger, I've got a few boxes of TMX in 4x5 and a roll of 8x10, maybe I should sell them for Delta before I shoot something I love and can't print.

I've had a bit more of a think about using a paper cutout, I don't think that'll work too well on 6x7 because the neg might sag in the middle.
Also kind of defeats the purpose of having a glass carrier, if I'm going to use masks I may as well have gotten a glassless 645 and 67 (for the same price that a universal and ANR glass cost) and deal with unsharp/sag by stopping down.
Also, I've heard about things called 'ANR Spray', but I'm not sure what they are/do (or, as always, if we can even get them here). Are they like an anti-static spray that lightly coats it and looks invisible, or more like a wet-mounting thing?

Meanwhile, the print's dry so here's a sample (although I'm sure you all know what Newton Rings are already). It's in the sky, same as with the Ektar was in the sky. Not sure if that's because an area of almost uniform brightness/colour makes for a smoother emulsion, or if they're in other places too and just a lot easier to see in the sky.
Also, glossy side up, yes. Otherwise the print is backwards.

(extra points to Polyglot if he can pick where I took it).

I'm done in the darkroom today, chems are finished and I'm too lazy to mix more (and I'm hungry). I've got some other stuff to print next time on FP4, FP4+, and PanF+, plus a whole bucketload of Delta 3200. So I'll get some more testing done on all of them and see how they go...

 

[John Koehrer]

Dr Crouble, Are you sure the whorls in the sky aren't wormholes to another galaxy/dimension?

OK got that out of my system.
Now for something completely different. try putting a piece of transparent tape at the ends of the negative carrier to see if the additional separation eliminates the rings. If that does it, a sprayed on coat of paint may also be thick enough.

If you print the neg emulsion side up do you still have the rings? Just curious.

 

[Mainecoonmaniac]

Does humidity play a factor with Newton's rings?

 

[Mainecoonmaniac]

This is one reason I don't like glassed carriers. Another reason is they're dusty. They've never worked well for me

 

[Dr Croubie]

Hmmm, ironic if humidity has something to do with it. My darkroom doubles as a bathroom sometimes, I was actually having a bath Sunday morning when I decided to do some enlarging afterwards, the enlarger sits on a plank of wood over the bathtub.
So there was probably a fair bit of humidity going around there at the time, even if I did have the exhaust fan going for an hour or so during/after my bath.
That contradicts the general ethos of 'humidity helps keep dust down' though, I used to run the shower on hot for a while before hanging negs up to dry so they wouldn't get dust on them.

I think what I'll try next is a mask, maybe just tape to start with. But if I tape to support 135 then there'll be gunk on it when I go to do 120. I've got some Kodalith which is fairly thin, I borked developing an 8x12" sized bit so I've got a lot to play with, that could work.
Removing the bottom glass wasn't feasible, with end-of-the-strip shots (like the one above) it just hung down with no support at the other end.

 

[Hilo]

Humidity has something to do with it for sure.

To experiment with masks of carton, you don't need to tape them. Just lay them in the middle and put your negative over. Or lay your negative first and drop the mask on it. Cut out the opening slightly larger than the image. I assume you can then properly do the masking with your easel?

I guess it depends on each carrier, but I do like this: with the normal lights on and an A4 sheet of paper on a table I place the carrier on that. That way I see exactly where to place the negative and/or the mask. I close the carrier and bring it into the enlarger

 

[MartinP]

If the lower glass is removable, why not replace it with a carrier/mask/aperture of carefully cut and sanded thin plywood? Material down to a fraction of a millimeter is available from modelling shops, but I suppose something of a similar thickness to the glass is what you are looking for - plus some black paint. There are several 135 sized negative carriers (eg. Focomat V35) which use glass only on the upper surface, as that is usually the direction of the bow of the film, so the idea is not without precedent.

 

[ic-racer]

I'd use a glassless carrier for those problem films and not worry about it. Remember to warm up the negative and focus just before the exposure.

 

[PKM-25]

If the lower glass is removable, why not replace it with a carrier/mask/aperture of carefully cut and sanded thin plywood? Material down to a fraction of a millimeter is available from modelling shops, but I suppose something of a similar thickness to the glass is what you are looking for - plus some black paint. There are several 135 sized negative carriers (eg. Focomat V35) which use glass only on the upper surface, as that is usually the direction of the bow of the film, so the idea is not without precedent.

I'd pay big bucks to be able to not have to think about Newton Rings with Acros, Techpan, APX 25, Tmax 100 & 400, even have a new carrier built with lower museum glass, but I might be inclined to do the above, already have the material...

I'd use a glassless carrier for those problem films and not worry about it. Remember to warm up the negative and focus just before the exposure.

Well that is the good thing with 4x5, especially with Tmax films the base is much stiffer so I don't use a glass carrier. 6x6 & 6x12 is another story, Acros is a nightmare...

 

[Ken Nadvornick]

Non-contact between negative and glass is exactly what you want to happen. Just not so close that an interference pattern is produced. What you want is an air space separating the two surfaces that is sufficiently large to not allow for their formation.

Old-timer pros used to use corn starch or talcum powder. They would blow some in the air, then quickly pass their glass sheets through the cloud to pick up a few random microscopic particles. The glass was then used as a cover sheet for contact prints from their large format negatives.

My 8x10 contact printing procedure is similar. I have an 18x22 inch sheet of quarter-inch thick glass plate. It's not soda-lime, so there is no greenish tint. It's also beveled for safe handling. I chose 18x22 because it's very heavy, and because I can use the same-size neoprene pad from my Seal dry mounting press as the base (flipped over, yellow side down, black side up).

I bought a can of plain hairspray. No fragrances or other stuff. A lifetime supply for $3.99. After cleaning, I lay the glass on a towel-covered table in the basement. Then I spray a short even burst in the air above it, waving with my hand to disperse it if it appears too concentrated. The microscopic droplets will fall onto the glass, dry, and stick in place, unlike the loose corn starch.

This then becomes my cover glass. I've never had an instance of interference rings using this method. I've also never noticed the microscopic droplets being shadow-imaged onto the prints. The droplets stay put on the glass so they don't contaminate the negative. And this also allows the glass to be reused. The spray can then easily be washed off and reapplied when the time comes to again clean the glass.

This works so well for me that I've considered doing the same to the glass on my flatbed scanner. It's a V-750 and takes 8x10, but only if you lay the negative directly on the glass. I've had interference problems doing this in the past.

I've also considered trying it with smaller format glass film carriers, of which I have several. But the potential problem here is that with enlargement comes magnification. So I need to run some tests to see if the droplets would show on the prints in this context. My guess is that they might.

Ken

 

[cliveh]

Treat the cause and not the effect, use a glassless carrier.

 

[Ken Nadvornick]

Good when you can, but bad when you can't.

I had occasion to print from a large number of 35mm negatives made in the 1950s. They had been stored tightly rolled in their original metal film canisters for over 50 years. Even after refixing and rewashing and vertical drying with weights, there were still formidable lateral curling issues.

An ANR glass carrier was the only possible solution.

Ken

 

[cliveh]

Good when you can, but bad when you can't.

I had occasion to print from a large number of 35mm negatives made in the 1950s. They had been stored tightly rolled in their original metal film canisters for over 50 years. Even after refixing and rewashing and vertical drying with weights, there were still formidable lateral curling issues.

An ANR glass carrier was the only possible solution.

Ken

Well perhaps the OP isn't printing stored and tightly rolled film in their original metal film canisters which are 50 years old.

 

[Ken Nadvornick]

Perhaps not. And if he can successfully print his negatives glassless, then his interference problem is solved.

But from his description it sounds as if he can't print glassless. That's why he went to glass. That's also why I went to glass. And once one has been forced to glass, then interference patterns must be addressed and mitigated in ways other than returning to glassless.

Otherwise one is simply chasing one's tail in a tight circle.

Ken

 

[PKM-25]

Well perhaps the OP isn't printing stored and tightly rolled film in their original metal film canisters which are 50 years old.

It does not have to be that extreme, a fair bit of efke MF films curl or cup and lots of 35mm do. If I never had to use a glass carrier ever again I would be ecstatic but that's not the real world for a lot of us.

 

[cliveh]

It does not have to be that extreme, a fair bit of efke MF films curl or cup and lots of 35mm do. If I never had to use a glass carrier ever again I would be ecstatic but that's not the real world for a lot of us.

But for a lot of us it is.

 

[Ken Nadvornick]

But this thread is all about the rest of us for whom it isn't.

The title of the thread is Cursed by Newton's Rings. Which strongly implies that people interested in that topic are those who have experienced them. And those experiences cannot have happened without using glass carriers. And as Dan says, none of us would be using glass carriers if we didn't absolutely have to use them.

So given that some of us absolutely have to use them, saying that the best solution to Newton's Rings is to not use glass carriers means what? That we must instead accept fuzzy prints? Or no prints at all?

That will indeed cure the rings. But there are more variables impacting this problem than just those rings. It's like advocating that the solution to unemployment is suicide. Well, in a narrow academic sense that will indeed cure the unemployment problem...

:confused:

Ken

 

[cliveh]

But this thread is all about the rest of us for whom it isn't.

The title of the thread is Cursed by Newton's Rings. Which strongly implies that people interested in that topic are those who have experienced them. And those experiences cannot have happened without using glass carriers. And as Dan says, none of us would be using glass carriers if we didn't absolutely have to use them.

So given that some of us absolutely have to use them, saying that the best solution to Newton's Rings is to not use glass carriers means what? That we must instead accept fuzzy prints? Or no prints at all?

That will indeed cure the rings. But there are more variables impacting this problem than just those rings. It's like advocating that the solution to unemployment is suicide. Well, in a narrow academic sense that will indeed cure the unemployment problem...

:confused:

Ken

Ken, I think your analogy is a bit extreme, but you are correct about the OP title for which I don't have a solution.

 

[DREW WILEY]

I've posted on this subject many times before. For my own standards, going glassless is a non-option in any format. You can get anti-Newton sprays from the same outfits which sell scanning fluid, but it's also something I'd consider a last resort. You spray a cloud, swipe your neg thru
it, and hopefully don't inhale anything. But there's a risk that any significant degree of enlargement will show the stuff. The correct type of antinewton glass depends upon a variety of factors. One shoe doesn't fit all. But not many choices are available anymore. For little stuff - 35mm and med format negs - you can sometimes find used Gepe antinewton glass slide mounts. Otherwise, Focal Point would be your primary source for custom glass. If your glass is clean, it actually prevents dust from coming into focus on the emulsion itself, unless you are using an unncessarily small f-stop. You can try optically-coated picture glass, but it has never worked for me in this foggy climate.