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.

[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.

[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