Are mirror coatings more durable then they were in the past? I did recommend it 20 years ago and they looked great, but I had gotten away from it due to peeling and scratching issues. Has the technology improved?
Are mirror coatings more durable then they were in the past? I did recommend it 20 years ago and they looked great, but I had gotten away from it due to peeling and scratching issues. Has the technology improved?
The technology has well advanced ...............................
Originally Posted by Michael I. Davis
Optical lens vacuum coatings are not the invention of optical companies, but of a whole industry of its own. The optical part has just been adopted by some of the large corporations and the optical retailers are still believing that they are the only ones using it.
Maybe we should better look who else uses them and for what these coatings are tailored today.
.....................The term physical vapor deposition originally appeared in the 1966 book Vapor Deposition by C. F. Powell, J. H. Oxley and J. M. Blocher Jr., (but Michael Faraday was using PVD to deposit coatings as far back as 1838). Physical vapor deposition coating is a product that is currently being used to enhance a number of products, including automotive parts like wheels and pistons, surgical tools, drill bits, and guns. The current version of physical vapor deposition was completed in 2010 by NASA scientists at the NASA Glenn Research Center in Cleveland, Ohio. This physical vapor deposition coating is made up of thin layers of metal that are bonded together through a rig that NASA finished developing in 2010. In order to make the coating, developers put the essential ingredients into the rig, which drops the surrounding atmospheric pressure to one torr (1/760 of our everyday atmosphere). From there, the coating is heated with a plasma torch that reaches 17,540.33 degrees Fahrenheit. In the automotive world, it is the newest alternative to the chrome plating that has been used for trucks and cars for years .............
read all about it -----------------------> http://en.wikipedia.org/wiki/Physical_vapor_deposition
The technology has well advanced and even your tea spoon could be coated..............it is cheap and it is of good use for many things and not only for overpriced optical lenses.
Thanks Chris;
Should I be concerned with crazing problems like we can see with A/r lenses when the A/R and the substrate flex at different rates?
In regards to your question Dr. Davis, I use mirror coatings quite frequently and I don't have a whole lot of heartache associated with their application. I think a black flash mirror on a set of shades looks sexy as hell so I do bring it up with patients on a regular basis. Maui Jim does a nice flash application that I think is rather nice looking.
My advice is this, in regards to not only mirror coatings but glasses in general, "You can curb the wheels on a Mercedes Benz...doesn't mean it's not a quality car, just not invincible. What makes you think your glasses are any more damage proof than a luxury vehicle?"
"Strictly speaking, there are no enlightened beings; only enlightened activity." -Shunryu Suzuki
Up here in Canadaland I have noticed a trend for people wanting mirrors on their lenses like the ones we have on display. We've had a couple different companies apply some mirror coatings to see who we were going to send those jobs to. One indie lab sent us back lenses that looked like they were made in the early 80's. This is not as cool at it sounds. They were awful. Zeiss was able to do the best job with a mirror coat that mimic'd the sample we had sent in on a Barton Perreira which was also a mirror over a grad. The newer tech ones feel slicker and to me seem like a vast improvement over the mirrors of yesteryear.
........mirrors have always been metal
Yes Michael.............mirrors have always been metal, today even more so for a jazzy look and different color hues.
Applied on mineral glass there will for sure be no problem, however on plastic lenses mounted in plastic or metal frames you might get flex-stress, specially at low or high temperatures.
The manufacturer evaporates metal oxides under vacuum which then sets as a metal layers on the substrate, and the thicker it gets the harder it gets. If the adherence is good and the lens flexes the coating might crack, and if the adherence is bad and the lens flexes it can partially delaminate.
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