A/R on crown glass lenses

[Aarlan]

Hello all,

I need to ask this question. We do a few glass lenses still (about 5% of total), esp in PGX. We used to put an anti reflective coating on glass ALL the time years ago. It actually held up better than CR39 and early poly lenses because of all the issues that have been resolved with the newer coatings.

My lab called me back yesterday on a job that we had ordered...glass PAL with A/R.

Lab claims that A/R CANNOT be applied to glass...when the hell did that happen?

Are the new a/r coatings w/ foundation/basement coatings not compatible w/ glass?

Any thoughts?

AA

[chip anderson]

Ask Chris Ryser, he'll tell you how. It still holds up better than plastics with same, a) it's glass b) the coating is a form of glass c: Expands and contracts at the same rate as lens material (not the case with plastics).

If you want the lab to do it for you, find a glass lab with someone old working there.

Chip

[Judy Canty]

Hello all,

I need to ask this question. We do a few glass lenses still (about 5% of total), esp in PGX. We used to put an anti reflective coating on glass ALL the time years ago. It actually held up better than CR39 and early poly lenses because of all the issues that have been resolved with the newer coatings.

My lab called me back yesterday on a job that we had ordered...glass PAL with A/R.

Lab claims that A/R CANNOT be applied to glass...when the hell did that happen?

Are the new a/r coatings w/ foundation/basement coatings not compatible w/ glass?

Any thoughts?

AA

Just checked with Luzerne. We can apply Zeiss SET on glass lenses...in house.

[Aarlan]

that's what i thought... glass flexes less (good)...glass has a minimal coefficient of expansion( good)...matches well with coating materials (sio2?)..good.

My question changes to this- If we apply a foundation coat to make an A/R work better with cr39 and other plastics, does this add'l step make it WORSE with Glass...are these newer set ups not equiped to skip the foundation coating step?


Aa

[Judy Canty]

Logic tells me that glass, because it lacks the flexibility of resins, wouldn't need a hard coat to insure the adhesion of the coating. The surface is already hard enough.

[Chris Ryser]

There is a natural adhesion between glass and SIO2 (silicon dioxide, also glass) which is the main ingredient in AR coatings.

In the 1980s the AR would not hold properly on CR39 until a coating was placed in between between lens and AR, which was properly adhering to the plastic and so did the AR coating material adhere to it.

These days many labs have arrangements with Zeiss, Essilor or others like Hoya or all of them to use their recipies for whatever arengement they have made. These people apply the AR coating according to instructions and have no interest about the why and hows. They dont know that the start of AR was on optical instruments and cameras in the 1930s and has been around ever since.

In Europe glass is still a much used material and AR coating is much more popular than in North America where it is about at 34%.

[Judy Canty]

Dangerous assumptions, Chris. I wasn't around in the 1930's, but I do know how to do my research. Zeiss developed A/R to be used on binoculars and it was considered a military secret.

[rbaker]

While glass ophthalmic lenses are a rarity today they still represent the majority of precision optics lenses. AR coatings are readily available from these sources.

[tigerlilly]

FWIW, our lab will not do AR on glass. It's the only lens we offer that comes without AR. I'm not sure what the reason is, actually.

[rbaker]

FWIW, our lab will not do AR on glass. It's the only lens we offer that comes without AR. I'm not sure what the reason is, actually.

The process is different and therefore not economical in low volumes.

[rbaker]

You might want to check these guys out:

http://www.edmundoptics.com/technica...ings/?&viewall

or Google ( "ar coating" -eye -glasses )

[Aarlan]

The process is different and therefore not economical in low volumes.

That's what I was looking for...that the process has become more specialized to accommodate plastic, that now many labs won't do glass, even though theoretically it should work better with an older method (without basement/foundation coat).

AA

[optilady1]

@Aarlan, just be aware, many of our local connecticut labs will do a/r on glass but won't warrenty it. This became an issue for my with my own 86 year old grandfather. I do believe if yougo with some of the more 'specialty' labs, they do come with a warrenty.

[Judy Canty]

Luzerne fabricates glass in-house, coats glass with Zeiss SET in-house and the warranty is for 1 year.

[chip anderson]

I'm not sure but I don't think the AR on Glass is heat sensitive, due to the expansion rate of the lens and substrate being the same or nearly so.

Chip

[Lee Prewitt]

Aarlan,

You should be able to AR glass with any "house" coating. iCoat's Fusion XTO, Zeiss SET, etc. If you order Avance or something similar your lab will say no because you can not run a glass lens through the special hard coat process.

[jefe]

Hello all,

I need to ask this question. We do a few glass lenses still (about 5% of total), esp in PGX. We used to put an anti reflective coating on glass ALL the time years ago. It actually held up better than CR39 and early poly lenses because of all the issues that have been resolved with the newer coatings.

My lab called me back yesterday on a job that we had ordered...glass PAL with A/R.

Lab claims that A/R CANNOT be applied to glass...when the hell did that happen?

Are the new a/r coatings w/ foundation/basement coatings not compatible w/ glass?

Any thoughts?

AA

Look at your camera, binocular, telescope and other such devices with lenses -- glass with AR.

[chip anderson]

As long as we are trending that way, do any of you youngsters know why the lenses in telescopes, microscopes, binoculars, ophthalmic instruments and the like are glass? Why they are not CR-39, or God forbid Poly, or trivex?

Chip

[Wes]

As long as we are trending that way, do any of you youngsters know why the lenses in telescopes, microscopes, binoculars, ophthalmic instruments and the like are glass? Why they are not CR-39, or God forbid Poly, or trivex?

Chip

Several reasons come to mind.
1. Back in the day, it was the only (good) optical material.
2. Later, back in the day it was the first material to easily AR coat.
3. It's STILL the best material available for such instruments due to rigidity, optical clarity and abbe values. The needs of optical instrumentation are different from the needs of a patient: weight, impact resistance, appearance, etc.
So what's YOUR answer?

[Chris Ryser]

WhitneyWeb Page
American Optical History
AO's Anti- Reflection coating development/products-
an industry leader in this technology



Time
42.10 (Sept 6, 1943): p90. (133 words)
Full Text:COPYRIGHT 1943 Time, Inc. "The glare has been removed from glass. The first practical process for treating big and small surfaces to eliminate lightreflection was announced this week by its inventor, H. R. Moulton of the American Optical Co. An improvement over a previously developed vacuum process for treating small glass surfaces, Moulton's invention is a simple coating that makes glass and other materials nonreflecting--and virtually invisible. Restricted to military uses for the duration, it will provide the postwar world with such useful things as: spectacle lenses that will cut out bright-light reflections for their wearer and be almost invisible to others; glareless car windshields; more visible dashboards and instrument panels; store windows, showcases, picture frames, watch crystals and clockfaces so clear that the glass is invisible;-faster camera lenses, producing sharper pictures; clearer movies and television."




http://www.dickwhitney.net/AOARCoatingsPage.htm

[chip anderson]

Odd how of all those projected uses, only a couple actually came about. Several not listed like eyeglasses did, but a whole lot didn't make the cut.

[optilady1]

My tv has an antiglare coating on it. It's no super high vision, but it does make a difference.

[CCGREEN]

Since we are on the subject: when you have a bright light shining in your face, is that glare? or is that reflection? Well of course it is glare.

Now when you shine that light on a smooth surface.....does it reflect or does it glare? Well of course it reflects.

Now when you look out across the water, or the horizon, what you see, is that reflections or glare?

So when you put a anti reflective coating on a surface to reduce the reflections why do so many people call the anti reflective actions/properties, glare? Because they feel the leftover reflection is glaring back at them? Then you have a poor anti reflective coating.

Just wondering why we in the business use those two terms in the same sentence and they both seem to be so opposite of each other.


Now here is something that should be simple for some........why is it the spell check button on this site does not work......or am I just special? Look I know I can spell well and I sure could use it.

[Judy Canty]

Since we are on the subject: when you have a bright light shining in your face, is that glare? or is that reflection? Well of course it is glare.

Now when you shine that light on a smooth surface.....does it reflect or does it glare? Well of course it reflects.

Now when you look out across the water, or the horizon, what you see, is that reflections or glare?

So when you put a anti reflective coating on a surface to reduce the reflections why do so many people call the anti reflective actions/properties, glare? Because they feel the leftover reflection is glaring back at them? Then you have a poor anti reflective coating.

Just wondering why we in the business use those two terms in the same sentence and they both seem to be so opposite of each other.


Now here is something that should be simple for some........why is it the spell check button on this site does not work......or am I just special? Look I know I can spell well and I sure could use it.

Why? Because a major lens and coating manufacturer tells us to and calls it education.

[Chris Ryser]

Why? Because a major lens and coating manufacturer tells us to and calls it education.

I just love that answer and remember that them same people also take care of continuing education at the Vision Expos.