Anti newton glass history & usage wanted

[Tin Can]

Does anyone see a loss of resolution while using one or two AN glass? In contact prints, enlarging and/or scanning?

Are there significant differences in AN glass?

What is the history of AN glass manufacturing and usage?

Is it a coating or surface treatment?

I have a pile of AN that is old, not for sale. Of course it is not stacked, but stored vertically and not touching.

Finally, does AN glass wear or become degraded with careful cleaning?

An expiring mind wants to know...

This thread from 2016 does not answer all questions. (https://www.largeformatphotography.info/forum/showthread.php?130139-What-is-anti-Newton-ring-glass-exactly&p=1322691&viewfull=1#post1322691)

[Bob Salomon]

The coated ones can wear off. The etched ones can’t.

[Peter De Smidt]

Traditionally, it was only used in the top of the carrier, with the shiny side of the film against it, but some current films are quite shiny on both sides. I've never heard of a problem when using it on the top. There are differences in the quality of the texture. Durst had a very fine texture. I believe that Howard Bond tested for quality loss using AN for both plates. If I remember correctly, he didn't see an issues at his enlargment sizes. I believe that Drew uses both and upper and lower sheet of AN glass in his carriers. I'm sure he'll correct me if I'm wrong. I'll also point out that some high-end scanners, e.g. Cezannes, scan through an anti-Newton (Leibnizian?) material, although this is usually acrylic. So, step one. Do you get Newton's rings? If so, try AN glass on the top carrier. Still have them? Try adding a bottom sheet.

[ic-racer]

I never even thought about it. With 1.4 to 2x enlargements of 8x10 small loss of resolution would not be noticed. I do enlarge 35mm, 16mm and Minox with anti-Newton glass. I think my prints are always better when the corners are sharp and there are no Newton rings, so I continue to use AN glass for everything.

My only issue with Newton rings was contact printing 8x10 over ten years ago. My thick glass was not AN glass and the Newton rings were horrible. What I did was to slightly lift up the glass and set it back down and quickly start the timer. If you watch the Newton rings (they are very visible to the naked eye) they move around a little until they settle in a stable pattern. So, during the exposure they are moving and would not be seen (if the exposure is short enough).

[ic-racer]

For example in this 16mm enlargement, the sharp edges of the sprocket holes are very well defined, in spite of the rays traveling through AN glass during enlargement.

187856

[PRJ]

I've used various anti newton glasses over the years. Some weren't even glass. I used cheap anti glare plexi for a while on one enlarger for example. My Leitz Focomat right now has anti newton glass from a 6x6 medium format glass slide mount. I've never noticed an issue, even with the plastic. I am pretty picky too.

With some films you can get issues on the emulsion side. Acros is one in my experience. In my Saunders the bottom glass is plain glass. Corn Starch solves the problem though. In my Focomat the bottom glass is coated and I've never had any newton rings with the coated glass and Acros.

I think the perfect solution is anti newton glass on top and coated glass on the bottom. I don't know if you can get coated glass in a large enough size though. If anyone knows of a source I'd love to change my Saunders carrier to coated glass.

[Tin Can]

3rd time in 2 days I recommend Glennview Camera as he sells coated glass and not AN.

I am waiting for more cash and plan to try his 5X7 coated glass sandwich.

He cuts to smaller if needed.

[Peter De Smidt]

I have a friend who tried coated glass in the enlarger. It was very expensive. He doesn't use it anymore. The problem was that the coating on specialty coated items tend to be very delicate, at least it was in his case. It's too bad that we can't get the right-sized glass sheets with modern multi-coating, complete with a hardened and smudge resistant outer coating. In any case, multi-coated glass will minimize Newton's rings, but I'm not sure that they will minimize them enough to not be noticeable.

[Tin Can]

Good to know Peter.

I want the Gorilla glass on my phone, it's tough as nails.

[Tin Can]

http://www.valleydesign.com/gorilla-glass.htm

[Drew Wiley]

Hi Randy. It's the only way I've done it over the past 40 yrs. At one time I tested over 13 types of AN glass options. For LF work modern Focal Point AN glass is fine. True Durst or Omega AN glass is better. No impact on sharpness if evenly compressed. Maybe something like a condenser head or point light source for 35mm film, combined with a high angle of incidence (shorter than "normal" enlarger lens) might have problems on a hard paper grade. A diffuse head works great. Coated optical glass might work in low humidity conditions, but sure doesn't here on the coast. I've tested all kinds of those too.

[Tin Can]

Humidity is rising here.

My 10 sheets of 8X10 AN glass came with mystery film carriers. Nobody here could identify their source years ago.

I'll try those first for enlarging and have used them for scanning top and bottom.

My 2 Leitz 35mm have AN bottom.

This week I enlarged Tri-X 320 in Negaflat, no AN, film in CB7 3 days and never touched. Still tight as drum. NOS Black CB7 Condenser head using 250 watt 213 lamp reduced to 100 watts with Variac, no filters. Got results I wanted. i need to find my 212 bulbs...

[Drew Wiley]

Going glassless is a crap shoot.

[Tin Can]

Life is a crapshoot

Roll the dice

Nobody gets out


Going glassless is a crap shoot.

[Cor]

I quit using AN glass on top of my negatives when I noticed that under certain conditions (which they were excatly I have to look up again) the pattern of the AN glass showed in my prints.

I use a Durst Laborator 1200 with Durst AN glass, for my negatives upto 6*6 I used to use a AN glass up (towards shiny side negative, and a mask (so glassless) at the bottom. Now I use only plain (Durst) glass. Finger crossed, no Newton rings. Oh and I use condensors only.

Best,

Cor

[Tin Can]

I would expect AN glass would add a pattern.

Thanks for your real life experience.

[neil poulsen]

I heard that the early AN glass that Durst themselves made was etched. But, the AN glass made by "Durst USA" in my neighboring town of Hillsboro was a very high quality glass made in California that was coated. I have a sheet of this for 5x7.

[Tin Can]

Neil, do you know how it was coated and with what?

Does it have a pattern?

Does it wear off when cleaning?


I heard that the early AN glass that Durst themselves made was etched. But, the AN glass made by "Durst USA" in my neighboring town of Hillsboro was a very high quality glass made in California that was coated. I have a sheet of this for 5x7.

[Drew Wiley]

AN glass was never coated. OCLI in Santa Rosa CA was the biggest coating lab in the world, by far. It had several big divisions which were all sold off separately. What Jens alleged to sell was a multicoated Schott Glass, and he told me in person he got it from Europe. The company which made Durst AN glass was in Belgium, and that product line is no longer in production. The reason Jens wanted a thick Schott glass is that he couldn't drill the extant AN glasses for AN pins. The last of the Belgian AN glass that could be cleanly drilled disappeared a long time ago. What I do is precision grind a shallow slot in the glass, then epoxy in a thin registration strip instead of drilling. But who knows?? Jens had a well-earned reputation for never shipping things he took money for; so maybe he couldn't get even the MC glass, and was running on a bluff. The only non-textured, coated AN glass I have that really works well came in big sheets from Zeiss. It's a very unusual coating and quite tough, and I've never been able to specifically identify it, or locate anymore than the original box I bought, which was obviously surplus from some custom run.

[John Kasaian]

Drew, as you well know there are thousands of acres of anti-Newton figs growing here in Fresno, California LOL!

[Drew Wiley]

I sure don't miss the summer heat in your part of the world; but I do miss all my various fruit trees, grapes, melons, and about a dozen other crops the heat would make sweet. Store bought just ain't the same. Of course you knew that the anti-Newton movement arose when a fig hit Sir Isaac Newton and splattered atop his head, and he wondered why, and how to stop it by figuring out a fancy formula manipulating gravity. Never worked. Seagulls would have been even worse. Any football jock knows that the best way to deal with that sort of thing is to simply wear a helmet and ignore all the math.

[gijsbert]

Speaking of AN glass, does anybody know how if Focal Point is still in business? I am looking for AN and regular glass for a Durst M805 bimaneg and I've tried to contact Focal Point a few times this month with no reply.

[gijsbert]

eBay says 'this seller' is away, it's been like that since Januari at least. So if anybody has another source that can cut to a given size and cleanup/chamfer the edges, I'd be all ears.
Cheers.

[thornhill]

eBay says 'this seller' is away, it's been like that since Januari at least. So if anybody has another source that can cut to a given size and cleanup/chamfer the edges, I'd be all ears.
Cheers.

You could try KHB Photografix in Canada.

[robbiemcclaran]

I was having trouble with newton rings making contact prints. I replaced the glass in my contact frame with a semi frosted non-reflective glass from my picture framer. Cost me 20 bucks and no more newton rings, no weird patterns form the glass.
Cheers!

[Drew Wiley]

Picture glass tends to be rather thin and fragile. For larger contact frames a thicker AN glass would be more desirable.

[Neal Chaves]

I have used a piece of anti-Newtons ring glass under the enlarger lens when printing for a vintage look. Only for part of the exposure. Gives an Imagon lens look to a sharp negative.

[Bob Salomon]

I have used a piece of anti-Newtons ring glass under the enlarger lens when printing for a vintage look. Only for part of the exposure. Gives an Imagon lens look to a sharp negative.

Not if it is on the base side.

[Pere Casals]

I have used a piece of anti-Newtons ring glass under the enlarger lens when printing for a vintage look. Only for part of the exposure. Gives an Imagon lens look to a sharp negative.

Another way is to defocus a bit the image (rotating the focus knob, or changing head height...) for part of the exposure. IMHO it's not the same result than with a soft focus lens, but sure it's also a soft focus effect.

By experimenting this (defocus in the exposure course) we find that image can grow or shrink when moving focus, delivering different effects, we can also defocus both up and down...

[Bob Salomon]

Another way is to defocus a bit the image (rotating the focus knob, or changing head height...) for part of the exposure. IMHO it's not the same result than with a soft focus lens, but sure it's also a soft focus effect.

By experimenting this (defocus in the exposure course) we find that image can grow or shrink when moving focus, delivering different effects, we can also defocus both up and down...

Some people would call that effect out of focus! True soft focus retains some sharpness.

[Pere Casals]

Some people would call that effect out of focus! True soft focus retains some sharpness.

It all depends on the share of exposure time the image is in focus, it is a true soft focus image because we have a totally sharp image component and a blurred image component.

Another control factor is the amount of defocus we provide while exposing the defocus time share.

With the enlarger method if "sharp time share" is 90% then sure that the print wil also retain a lot of sharpness.

This can also be easily simulated in Ps, by adjusting the blend of the sharp image layer with a more or less blurred layer.

But for shure that a soft focus lens is a different thing, because the effect also may depend on the DOF/OOF position of each spot, as corrections work different through focus. IMHO soft focus lenses have a beautiful bokeh vs soft_focus interaction.

[Bob Salomon]

It all depends on the share of exposure time the image is in focus, it is a true soft focus image because we have a totally sharp image component and a blurred image component.

Another control factor is the amount of defocus we provide while exposing the defocus time share.

With the enlarger method if "sharp time share" is 90% then sure that the print wil also retain a lot of sharpness.

This can also be easily simulated in Ps, by adjusting the blend of the sharp image layer with a more or less blurred layer.

But for shure that a soft focus lens is a different thing, because the effect also may depend on the DOF/OOF position of each spot, as corrections work different through focus. IMHO soft focus lenses have a beautiful bokeh vs soft_focus interaction.

Of course, changing focus or head height during exposure will also add vibration! Unless, perhaps, if your enlarger has motorized elevation and/or focus.

A true soft focus lens diffuses the highlights into the shadows, that requires a greater lighting ratio, and lenses like the Imagon also have greater depth of field at the same focal length, distance and aperture.
Stockings, soft focus attachments or your technique will not give that look.

[Pere Casals]

Of course, changing focus or head height during exposure will also add vibration!


Yes, but that vibration is irrelevant because the sharp component was already exposed, and the vibration of the blurred component has no effect because that component is blurred anyway.

Of course we first expose the sharp component and later we defocus, not the reversed order.



A true soft focus lens diffuses the highlights into the shadows, that requires a greater lighting ratio, and lenses like the Imagon also have greater depth of field at the same focal length, distance and aperture. Stockings, soft focus attachments or your technique will not give that look.

Of course, no doubt. A soft focus lens has, in fact, amazing aesthetic nuances that come from the scene 3D, and this may be very difficult to emulate from a yet flat image.

Also, there is nothing wrong in using other resources, like generating a soft focus with the enlarger or with Ps. IMHO soft focus glass is linked an entire aesthetic culture of inmense value. But if one has a sharp negative then making a soft focus with the enlarger it is a choice, this is just a different creative tool we have.

To me the Soft Focus glass is clearly a more powerful tool, but we may prefer the other way for a particular situation.

[Neal Chaves]

Here's an example of the use of a piece of ANR glass for print manipulation. I held it under the lens, moving it slightly, for about half the print exposure. Notice how the highlights have smeared into the shadows. I have heard this described as "D-Max Glow". I think it can be produced with other diffusion materials, but I liked the effect obtained with my piece of ANR glass, the molded type, with the ANR surface facing up towards the enlarger lens.
188877

[Tin Can]

Interesting!