Does anyone know the web site for COLTS Lab?

[Spexvet]

I've done various web searches for COLTS lab, but I can't seem to find a home page. They've published some great test results in the periodicals over the years, and it would be nice to be able to cite their site as a reference in a post.

I remember reading results that showed when AR is applied to poly, any ABBE value issues virtually diappear. At least that's how I remember it.

[impact500]

http://www.colts-laboratories.com/

First class operation.

[Spexvet]

http://www.colts-laboratories.com/

First class operation.
Thank You!

[Pete Hanlin]

If you find that article on the relationship of Abbe values and anti-reflection coatings, please let me know. I don't believe there should be any relationship between the two- since dispersion is a product of prism and the inherent properties of the material (abbe). If there is a relationship between chromatic aberration and AR (and I've heard numerous individuals state that there is- but without any reason or reference), I'd like to understand why.

I believe you'll find a phone number at the web site. If not, let me know- John Young (owner and President of COLTS) is right across town from my office.

[coda]

I have also heard this rather tenuous claim (AR eliminates Abbe problems) a number of times. I believe the observers are actually seeing a reduction in non-Abbe related chromatic dispersion. I have seen a number of professionals mistake the chromatic effect of index mismatch between a hardcoat and substrate (often colloquially known as 'hardcoat ripple') as a result low Abbe. For some reason this effect (hardcoat ripple) is particularly visible on polycarbonate lenses, when you slap an AR on that lens the ripple is considerably less visible. Hence (putting together these observations with incorrect assumptions) AR eliminates Abbe problems.

My science says Abbe is a volume only property, AR can't (and doesn't) change the volume properties of a lens ergo AR doesn't mitigate Abbe problems.

Another observation on evaluating low Abbe lenses. It's difficult for people with low scripts to evaluate the chromatic dispersion related to Abbe because 1. low scrips won't exhibit much dispersion and 2. when looking through a high power lens they are so focused on how 'painful' the view is as a result of the high power that they find it difficult to evaluate the relativly low levels of chromatic dispersion.

EDIT: I should also point out that I believe that Colts does a good job at what they do. I also don't think they would have made any arguments about AR-Abbe interactions, Colts generally doesn't report results or opinions (beyond their certifications) they leave that up to the people who contract the testing. Of course one can draw any inference they want from test results regardless of how silly they are.

[Spexvet]

I found the article! It is "Coating Poly" by John Young, of COLTS Lab. 20/20 magazine July, 2001.

About chromatic aberation in low Abbe materials, like poly, he says "In our industry, some say there is less of a problem when A-R coatings are used. While I have no scientific or clinical proof this is so, it is somewhat plausible".

So I guess my memory is not as complete as my tendancy to horde pages of articles ripped out of magazines. Good thing that's still intact.:hammer:

[mrba]

yes but poly is particularly scratch prone when coated...

[rinselberg]

yes but poly is particularly scratch prone when coated...Could we play Amateur Hour here, for a moment? The post from mrba has me a little puzzled. Poly, before it is coated with anything, is soft and scratch prone -- right? Poly has to be coated with either SRC (scratch resist) or AR (anti reflex) to be usable, right? Is mrba saying that a poly lens with a good SRC (but no AR component) is a sure bet to be more resistant to scratching than the same poly lens with even the most scratch-resistant AR package (foundation, AR and topcoat) that's available -- whatever AR product that would translate to, in your (professional) estimation? Or is mrba saying that poly is scratch prone when AR coated, unless you skip over the middle of the pack ARs and select one of the most scratch-resistant AR packages available --? Or is mrba saying that in general, compared to certain other AR coated lens materials (you fill in the materials, please), AR coated poly is not likely to prove as scratch resistant?

[mrba]

Could we play Amateur Hour here, for a moment? The post from mrba has me a little puzzled. Poly, before it is coated with anything, is soft and scratch prone -- right? Poly has to be coated with either SRC (scratch resist) or AR (anti reflex) to be usable, right? Is mrba saying that a poly lens with a good SRC (but no AR component) is a sure bet to be more resistant to scratching than the same poly lens with even the most scratch-resistant AR package (foundation, AR and topcoat) that's available -- whatever AR product that would translate to, in your (professional) estimation? Or is mrba saying that poly is scratch prone when AR coated, unless you skip over the middle of the pack ARs and select one of the most scratch-resistant AR packages available --?
First of all, your font, is so darn small I can barely read your question, however, I am aware that may not be your fault:bbg: .

Good question. Polycarbonate by itself is extreamly soft. As a result most poly lenses come with a very tough hard coat which make them scratch resistant. The best of these are thermal cured coatings.

When basic AR is applied to these lenses the ar is much more prone to scratching, because despite the hardcoat on poly, the substrate is still quite soft relative to plasic.

However, you do bring up a good point with Carat/Crizal etc. These AR coats are applied to a new hard-under-coat (TD2 or Foundation) that does increase durability.

Or in english...
Or is mrba saying that in general, compared to certain other AR coated lens materials (you fill in the materials, please), AR coated poly is not likely to prove as scratch resistant
Yes.

[rinselberg]

Thanks! If I read you correctly, what you are saying is that if I were to decide that I wanted to have AR lenses in poly, I would need to make sure that it is a real good AR product such as Carat, Crizal and perhaps a few others we could agree on -- but nothing less than the best in the AR department -- right? Assuming of course, I was concerned about scratch resistance!

[mrba]

affirmative.

[Spexvet]

I find that the scratch resistant poly I get from my lab is as scratch resistant as any other scratch resistant material. And the premium AR are much more scratch resistant (and craze and peel) resistant than the cheap ones.

Rinselberg, don't sweat the scratch issue. Clean your lenses by running them under warm water, soap them up with dish detergent (dawn-like), rinse them, and dry them with a clean, cotton cloth. If you clean them this way (no paper, no windex, and don't take them off and rub them with your shirt or tie) you will not scratch your lenses. Take some responsibility for the condition of your lenses - after all lenses don't scratch themselves, people scratch lenses.

PS - Also, don't drag them across a conrete floor with the lenses face down.

[mrba]

Poly AR is the hardest lens to get out of the lab without a scratch. Ask any lab guy, it's no secret!

[Jacqui]

Poly AR is the hardest lens to get out of the lab without a scratch. Ask any lab guy, it's no secret!


I agree, it's NASTY :(

[rinselberg]

Poly AR is the hardest lens to get out of the lab without a scratch. Ask any lab guy, it's no secret!Hello all. Is that because of what goes on in the lab during the processing of the lenses? Or -- are these the same kind of scratches that the lens wearer would be likely to cause?

[Spexvet]

Poly AR is the hardest lens to get out of the lab without a scratch. Ask any lab guy, it's no secret!
But when I get them, they are already back side coated. Are you saying that once coated (front and back), a poly lens, without AR, will scratch more easily than a scratch resistant CR-39?