As we know that in the market now we have several multicoat color, Green, Blue, Gold, Purple, Yellowish..... but did any one know that can we make the coating to be "NO COLOR" multicoat?
As we know that in the market now we have several multicoat color, Green, Blue, Gold, Purple, Yellowish..... but did any one know that can we make the coating to be "NO COLOR" multicoat?
Originally Posted by samwkn
Gee, I wonder what manufacturer you work for?
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
LOL...he's in Malaysa. And it is relatively new technology to claim a no-color AR, but I'd like to see it to believe it.
There are several Clear AR's on the market. Since most Far East lens manufacturers use chemical AR coatings it shouldn't be hard for them to modify the recipe and get a clear coat.
first, all ar's use chemicals. second, the physics are impossible. the way that interference coatings works predicates that only one wavelength at one angle of incidence will theoretically reach no reflection. any claims to the contrary must rely on some radical new break through technology or much more likely are snake oils.
We have to remember, the colour is there for a reason
By chemical I meant wet coat like Chemlux (it's called chemical in the Far East). There are several brands of clear AR from such names as Essilor, Kodak and a few other biggies, check them out.
Why??
because no one's found a way to eliminate it. i did find an interesting article though. http://www.freerepublic.com/focus/f-news/1794445/posts this could be that radical break through that i mentioned. be sure to read to the bottom however for information concerning application to ophthalmics. it's dated over a year ago, but i doubt that's time enough to make it practical.
---edit---
also, whether it's the ar stack is delivered via liquid or vapor the same technical hurdles still exist. the advantage of vapor deposition vs. liquid spin application is thinner layers allow for more layers and therefore, a more complex and effective stack to be engineered. chemlux uses a simple three layer "high, low, high" stack and alters the spin speed to control layer thickness. the thickness of the layers controls the targeted portion of the spectrum. it's a bit like tuning an antenna to make an analogy for any of you ham operators out there.
Last edited by coffee joe; 08-24-2008 at 05:25 PM.
because there is still a residual glare off the lenses. There is no AR coating that eliminates 100% reflections. So to compensate, some scientists, who are far more educated in their fields than I, found several colours that tend to be less visible than glaring white light. They then used one of those colours for the lens.
From my limited (none) knowledge of physics, would a (in this case) lens that did not reflect light absorb it? If there was no colour would it be absorbing 100% of light, thus be akin to a black hole?
On the flip side of this is a mirror that reflects light. If it reflected more than 100%, would it be producing light?
I know it is possible to get the reflection really low, but to have no colour seems unlikely or impossible. Perhaps I dont know enough or there is technology that can do it. I would like to see it though.
I don't know, there are companies selling CLEAR AR. There was also someone at VEE that was producing some that were almost invisable (you had to look hard to see the lens). Most of the colour comes from metal oxides that are layered with the silicon dioxide during the coating process, what would happen if these were left out?? Would the coating be clear or almost clear??
You would have to put many layers into a coating to get it to zero (or near zero) reflectance, as I am led to believe that the layer you put on must be the square root of the preceding layer to achieve no reflectance.
I think that the lowest index of material (able to be used in coating machines) is Silcon Monoxide or Magnesium which has indeces of 1.46 and 1.38 respectively. You need 1.22 to get zero reflectance from 1.498 Plastic.
As said before I have limited knowledge in this, but this is what I am led to believe......unless it is a cunning plan by the coating companies to keep me buying their products!!!!!
Did anyone know where can i get a sample at the market?
I have no idea how is the coating look like.
We have a RX lab, Edging Lab and also MC Lab.
We have a RX Lab, Edging Lab, and also MC Lab.
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