Lens coating, who, where?

[bojan]

Does anybody know about someone who can deposit antireflex coating on the lens?
I recently acquired 100mm dia air spaced doublet.. and perhaps it would be worth doing this (pending on test, of course..)

[Stefan Buda]

Hi bojan,

I have a vacuum system that I use for coating my own lenses, but it can do only single layer magnesium fluoride.

Please let us know if you find someone that can do broadband multilayer coatings, as my next astrograph project will require very high transmission coatings.

Cheers,
Stefan

[blink138 (Pat)]

hi bojan i am sure i can get it done for you here in perth
one of our other iis members had a similar request (alex) on here and i have a good mate in a local opthalmic lens laboratory with state of the art vacuum chambers
the only issue could be because it is made for opthalmic purposes the largest lens blanks we use are 75mm, but if you wish i could recheck?
pat

[bojan]

Thank you guys for the information
I still haven't determine if this lens is worth the effort.. it is cloudy here in Melbourne...

[Eden (Brett)]

These guys will be able to assist:

Optical Coating Associates

I have dealt with them and they are extremely helpful. Be aware, however, that they only provide optical coating services. They are unable to remove existing coatings, so you will need to find someone who is able to do that first.

[astroron (Ron)]

Originally Posted by blink138

hi bojan i am sure i can get it done for you here in perth
one of our other iis members had a similar request (alex) on here and i have a good mate in a local opthalmic lens laboratory with state of the art vacuum chambers
the only issue could be because it is made for opthalmic purposes the largest lens blanks we use are 75mm, but if you wish i could recheck?
pat

Pat, I have a 13mm nagler type 1 that needs a recoat could you check if they can do that?
I checked with Teleview and they won't do it.

Cheers

[blink138 (Pat)]

Originally Posted by astroron

Pat, I have a 13mm nagler type 1 that needs a recoat could you check if they can do that?
I checked with Teleview and they won't do it.

Cheers

hi ron, we would need of course to remove the offending element from the system, would that be able to be done do you think?
could do it i reckon if this could be done, again though as above i would need to check
pat

[astroron (Ron)]

Originally Posted by blink138

hi ron, we would need of course to remove the offending element from the system, would that be able to be done do you think?
could do it i reckon if this could be done, again though as above i would need to check
pat

Hi Pat,I see no reason why not it could not be removed,I have of course not tried to do it.
I could of course send it to you,it weighs about about half a kg so would be a few dollars.
I suppose you have the facilities to remove the old coating
I love this eyepiece and I was disappointed when Teleview would not repair it for me.
What are your thoughts on me sending it to you?
I will of course pay postage each way.
It has been my favourite eyepiece for just on 25 years,I purchased it in Pheonix Arazona in September 1990.
BTW what is your charge for the recoat,
Cheers

[Wavytone]

Regarding coatings, Francis Lord in sydney is another that can apply MgF or multilayer dielectric coatings.

As for removing them, MgF I think can be stripped off chemically but the multilayer ones, no.

The point is that the multilayer coatings usually involve zinc cryolite which produces a layer harder than most glasses and in addition, chemically inert. The only way to remove these coatings is to grind it off - implying that even if repolished the lens will then be thinner than originally, and wedge, radius and the final figure have to be controlled. Suffice to say it is not viable to remove a coating - it is a lot simpler and cheaper to replace the whole lens.

I know some will be attached emotionally to their Nagler or objective and unable to bring themselves to do it, but it's a simple financial reality.

[blink138 (Pat)]

Originally Posted by astroron

Hi Pat,I see no reason why not it could not be removed,I have of course not tried to do it.
I could of course send it to you,it weighs about about half a kg so would be a few dollars.
I suppose you have the facilities to remove the old coating
I love this eyepiece and I was disappointed when Teleview would not repair it for me.
What are your thoughts on me sending it to you?
I will of course pay postage each way.
It has been my favourite eyepiece for just on 25 years,I purchased it in Pheonix Arazona in September 1990.
BTW what is your charge for the recoat,
Cheers

jeez ron i have never removed an element before and never seen the inner workings of one
in the 1980,s i was the optical (opthalmic) technician for hoya lens here in perth and their multicoatings were superb.
this was in a time where opthalmic hi index plastics were very limited and on a number of occasions we had to strip multicoatings off some of their 1.8 refraction glass in an acid bath
all technology of course is now in hi index plastic lenses and glass is pretty much obsolete, it has been greater than fifteen years since i have dispensed a glass lens
i will phone my friend in the laboratory today
btw in my experience there are no "other" special coatings inert on glass that cannot be removed as wavytone mentions, anyhow i will ask
pat

[astroron (Ron)]

Originally Posted by blink138

jeez ron i have never removed an element before and never seen the inner workings of one
in the 1980,s i was the optical (opthalmic) technician for hoya lens here in perth and their multicoatings were superb.
this was in a time where opthalmic hi index plastics were very limited and on a number of occasions we had to strip multicoatings off some of their 1.8 refraction glass in an acid bath
all technology of course is now in hi index plastic lenses and glass is pretty much obsolete, it has been greater than fifteen years since i have dispensed a glass lens
i will phone my friend in the laboratory today
btw in my experience there are no "other" special coatings inert on glass that cannot be removed as wavytone mentions, anyhow i will ask
pat

Cheers Pat,I have a friend who is into eyepieces and will ask him if it is possible to do it and maybe just send the front element to you.
Look forward to what your friend in the lab says.
Cheers

[blink138 (Pat)]

Originally Posted by astroron

Cheers Pat,I have a friend who is into eyepieces and will ask him if it is possible to do it and maybe just send the front element to you.
Look forward to what your friend in the lab says.
Cheers

ok ron this friend just asked the vacuum chamber manager in the laboratory and he said although the mix of chemicals are the same for glass and plastic the application is different and that their ion gun is set up for opthalmic plastics which also need a hard coat applied first
i know hoya lens had two separate chambers for the two materials
he also said that when people phone about glass lenses they send them to a specialist glass lab in south australia, stand by and i will try and find them in my directory, if not i still know an old school optical mechanic in melbourne who may know someone
pat

[astroron (Ron)]

Originally Posted by blink138

ok ron this friend just asked the vacuum chamber manager in the laboratory and he said although the mix of chemicals are the same for glass and plastic the application is different and that their ion gun is set up for opthalmic plastics which also need a hard coat applied first
i know hoya lens had two separate chambers for the two materials
he also said that when people phone about glass lenses they send them to a specialist glass lab in south australia, stand by and i will try and find them in my directory, if not i still know an old school optical mechanic in melbourne who may know someone
pat

Cheers Pat.

[blink138 (Pat)]

ok got through to the glass lens lab in s.a and they deffinately need to strip any residual coating before any reapplication but they have not got the acid bath facility for stripping
i asked about buffing the original coating off but they said it is inadequate as the lens shatters when the ion gun fires and can potentionally damage their very expensive chambers
they were only prepared to coat new lenses
i will try one more person
pat

[Satchmo]

Saintech do all kinds of AR coatings for research and amateur astronomers.

Removing stains on lenses from gradually failed coatings might take an optician though .

[blink138 (Pat)]

hit a bit of a dead end at closing work on friday, one more lead on monday
pat