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Equipment Discussions >> Refractors

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Plane_Guru
member


Reged: 02/17/13

Refractor Anti Reflection Coating longevity.
      #5692268 - 02/21/13 07:10 AM

Hello everybody,

I-am interested to know your opinions regarding the longevity/lifespan of Anti-Reflection Coatings on Refractor Telescopes.

In your Opinion would UV Radiation from Sunlight have a detrimental effect on the Anti-Reflection Optical Coatings in Refractor Telescopes? Does continual bombardment by Solar Radiation from the Sun degrade Optical Coatings(like Anti Reflection Coatings) over time?

I am of the belief that Magnesium Fluoride is still the mainstay of Anti-reflection Coatings, and that this material has almost zero solubility in water and all common organic solvents. Another material commonly used in Anit-Reflection Coatings is Silicon Dioxide (Quartz) which is an extremely hard and tough material. I believe both Magnesium Fluoride and Silicon Dioxide (Quartz) are highly transparent to UV light, and so will have little interaction with Solar UV Light due to the transparency of these Materials.

I presume that the Solar Radiation ( Light Energy) that passes through Refractor Anti-Reflection Optical Coatings does not damage or degrade the Optical Coatings over time due to the light having little interaction with the Optical Coatings.

I also learned that Optical Coatings were originally developed to retard the migration of Fluoride out of Glass.

Many Thanks for your input.

Edited by Plane_Guru (02/21/13 07:11 AM)


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Starhawk
Space Ranger
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Reged: 09/16/08

Loc: Tucson, Arizona
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5692392 - 02/21/13 09:23 AM

The coatings are really glasses of various types. They should last indefinitely. The main coatings for cheap optics are magnesium fluoride. The nicer stuff has all moved on to much more sophisticated multicoated systems, which give themselves away with colored sheens, or in the really high end ones, by completely vanishing except for very careful illumination.

With that said, surface prep and processing are paramount for getting them on there properly. And if you ever deal with a coating vendor, you will discover they only warranty them for 1 year in most cases.

So what happens if anti reflection coatings fail or are damaged? I asked Roland about that, and his answer was it is more work to polish the coatings off, recorrect the figure, recoat, and put an optical set back together than it is to build a new telescope.

So take care of your coatings.

-Rich


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Starhawk]
      #5692402 - 02/21/13 09:33 AM

Hi Rich,

I am purchasing a new Televue NP-101 and Televue 60 IS Guidescope,I would hope the coatings would last indefinitely.I hope for the two Televue Telescopes to outlive me.


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Binojunky
Carpal Tunnel
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Reged: 12/25/10

Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5692550 - 02/21/13 11:18 AM

Providing you don,t get silly with constantly cleaning every minor blemish and mark off they will last a lifetime,DA.

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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5692915 - 02/21/13 03:06 PM

Only diamonds are forever. All else is subject to the ravages of time and misuse.

Seriously though, why the fixation on coatings? A well-cared-for refractor used and stored sensibly will outlast you, whether or not its coatings remain exactly as they were the day you took delivery of the scope.

In the grand scheme of things, the coating type and durability is way down the list of things to worry about when choosing a refractor. Coating type and integrity are not crucial for achieving excellent performance from a refractor. You can't say that about mirrored scope coatings, but you can about refractors.

Instead of worrying about coatings, I would worry about mechanical design, robustness of the optical alignment retention design (i.e., the lens cell), and above all optical figure quality. An uncoated excellent quality refractor will outperform a perfectly coated, poorly figured refractor every time.

Seriously, worry more about the optical quality and how well the scopes you're considering maintain optical alignment rather than coatings. Those are far more relevant concerns affecting enjoyable "lifetime" use and performance of a refractor.

Best of luck with your choice.

Regards,

Jim

Edited by jrbarnett (02/21/13 03:08 PM)


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KWB
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Reged: 09/30/06

Loc: Westminster,Co Elev.5400 feet
Re: Refractor Anti Reflection Coating longevity. new [Re: jrbarnett]
      #5693002 - 02/21/13 03:58 PM

Quote:

Only diamonds are forever. All else is subject to the ravages of time and misuse.

Seriously though, why the fixation on coatings? A well-cared-for refractor used and stored sensibly will outlast you, whether or not its coatings remain exactly as they were the day you took delivery of the scope.

Jim



I think Jim makes a very good point here,just like the one he made to the identical question asked in another thread.

To the OP,in the future,please just ask a specific question one time, in one thread.


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: jrbarnett]
      #5693017 - 02/21/13 04:04 PM

Hi jrbarnett ,

Thanks for the input.I was just curious as to the estimated longevity of Anti-Reflection Coatings because I am not wealthy and naturally I would hope that my expensive Televue NP-101 Telescope that I just invested in would outlive me .

Sadly these Days we live in a Throw away Society.I look after what I own .I love Science too and the Science behind Anti-Reflection Coatings.I love learning,in general.

All my best


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la200o
Carpal Tunnel


Reged: 09/09/08

Loc: SE Michigan, USA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5693099 - 02/21/13 04:38 PM

yer NP101 will outlive you, no problemo

Bill


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EdZ
Professor EdZ
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Reged: 02/15/02

Loc: Cumberland, R I , USA42N71.4W
Re: Refractor Anti Reflection Coating longevity. *DELETED* new [Re: KWB]
      #5693436 - 02/21/13 07:59 PM

Post deleted by KWB

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Starhawk
Space Ranger
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Reged: 09/16/08

Loc: Tucson, Arizona
Re: Refractor Anti Reflection Coating longevity. new [Re: EdZ]
      #5693475 - 02/21/13 08:17 PM

The only real failure I've seen in TV OTAs is the flocking coming off in the interior. In everyday life, coatings die from over cleaning and using the wrong materials.

So:

Plan A keep it clean- no touching, think before you take it out in blowing dust or pollen, and store horizontally.

-Rich


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Starhawk]
      #5693701 - 02/21/13 10:32 PM

Hi Starhawk,

Thank-you.I hope the Flocking Paper peeling is not a major issue with Televue NP-101 Refractor Telescopes?.Is Peeling Flocking Paper rare in Televue Refractor Telescopes?

I would hope that this issue has been rectified by now? Has Televue changed to better stronger Adhesive technologies by now?

Peeling Flocking Paper is a concern of mine due to the fact I reside in a Humid locale.


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5693714 - 02/21/13 10:37 PM

Hi,

While I am thinking of this..I also have to ask abut Dielectric Coated Star Diagonals? I read that Dielectric Star Diagonals supposedly never go bad due to the fact that Dielectric Coatings never oxidise and so should last "Forever" with no loss of brightness( performance)?


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5693795 - 02/21/13 11:47 PM

Brightness (reflectivity) of a diagonal is pretty much irrelevant. What are key are flatness, mechanical precision and smoothness of the surface. While a dieclectric coated diagonal won't need a recoat, they do tend to be rougher than standard coated mirror diagonals. Also, not all dielectric diagonals are created equally. Some have rougher surfaces than others. The A-P Maxbrights and TV Everbrites are in the middle in terms of surface smoothness. The GSO Quartz diecletrics are smoother, but mechanically the housings are a little flimsy. For my most critical observing (planets and double stars) is use a conventional mirrored turret.

Again, only diamonds are forever. There is nothing else under the Sun that will last forever. These items are tools. They are meant to be used, not put on display. A scope used every clear night for 10 years that then fails is still a better scope than one that lasts fifty years but isn't used by the owner for fear of it losing its "newness".

Refractors don't fail catastrophically. Wear items include the focusers and the retractable dew shade retention materials. Regular maintenance items include occasionally cleaning the front of the objective. Mishandling related maintenance might include recentering and/or collimating the objective. NP-101s are sensitive to decentering as all four elements need a common center and squaring. If you whack it hard on accident, you will either need to build your own jig and recenter the front elements relative to one another and the rear group or else send it off to Televue for service.

It's nice that Televue offers service. They will repair, clean, colimate, etc., Televue refractors for a fee. Of course, nothing lasts forever and one day Televue will fold or be acquired, and the days of readily available service may end.

Are you planning on imaging or observing visually, or both? What makes you think the NP-101 is your best option? There are many nice 4" and larger refractors available that cost much, much less than the NP-101. have you considered other makes and models?

Perhaps if you didn't spend quite so much, you'd be less worried about it lasting "forever" which is an unrealistic expectation, though pretty much any refractor is likely to outlast you and me.

- Jim


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la200o
Carpal Tunnel


Reged: 09/09/08

Loc: SE Michigan, USA
Re: Refractor Anti Reflection Coating longevity. new [Re: jrbarnett]
      #5694257 - 02/22/13 09:22 AM

Deflocking and loss of collimation are rare problems. Get your NP101 and don't look back. It can do things no other 4" refractor can do. Superb wide field views and great at high power. Wouldn't be without one, myself.

Bill


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Paul G
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Reged: 05/08/03

Loc: Freedonia
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5694405 - 02/22/13 10:36 AM

Quote:

Hi,

While I am thinking of this..I also have to ask abut Dielectric Coated Star Diagonals? I read that Dielectric Star Diagonals supposedly never go bad due to the fact that Dielectric Coatings never oxidise and so should last "Forever" with no loss of brightness( performance)?




The benefits of a dielectric diagonal are:
-- coatings don't degrade over time
-- they can be kept clean without risking damaging delicate coatings; dielectric coatings actually become part of the glass and must be ground off to remove
-- much less scatter than aluminum mirror diagonals (on a molecular level the aluminum coating is quite rough)

Some cautions:
-- not all dielectrics are the same
-- there are some cases of inexpensive dielectrics flaking off, a sign of improper surface preparation or improper application of the coatings
-- the coatings are designed to have maximum reflection for light coming in at a 45 degree angle, can be less reflective and /or more transparent if the light comes from a nonoptimal angle (for instance, shining a laser straight down on the mirror)
-- how the mirror is supported is important
-- how the diagonal is baffled is important
-- how the diagonal is designed to dissipate the small % of light that isn't reflected is important, you don't want that light reflecting around inside the substrate and coming out the other end (there has been at least one post here on CN where this dissipation was incorrectly thought to be scatter; scatter of the transmitted light isn't the same in terms of affecting the image as scatter that is reflected off the surface)

A good dielectric is likely to be the most accurate surface in the optical train. The AP Maxbright, for instance, is guaranteed to be at least 1/20 wave, most are around 1/40 wave.


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: la200o]
      #5694414 - 02/22/13 10:42 AM

Hi Bill,

Good to hear that De-Flocking is rare.I have a new Televue NP-101 on order.


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Paul G]
      #5694431 - 02/22/13 10:52 AM

"much less scatter than aluminum mirror diagonals (on a molecular level the aluminum coating is quite rough)"

Sadly, this is untrue. Having tested a host of diagonals, including the A-P Maxbright using a precisely spaced green laser and calipers to measure contact spot size on the mirror or prism first surface, even cleaned dielectric diagonals, on average, show larger contact spots (indicating greater surface scatter) than standard aluminum coated and quality prism surfaces. Theory is fine as far as it goes, but when it is accepted as fact without verification it becomes marketing hype.

Dielectric diagonals have more durable coatings, which is great because diagonals are rubbish bins collecting all kinds of junk and need to be cleaned, but you buy that virtue with the vice of higher scatter on average.

Now whether you can see the level of reduced scatter of a quality enhanced aluminum diagonal over a quality dielectric one at the eyepiece is debatable, but I hate to see the marketing myth of superior surface smoothness perpetuated as fact.

Regards,

Jim


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la200o
Carpal Tunnel


Reged: 09/09/08

Loc: SE Michigan, USA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5694476 - 02/22/13 11:21 AM

Quote:

Hi Bill,

Good to hear that De-Flocking is rare.I have a new Televue NP-101 on order.




You will love it.

Bill


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BCNGreyCat
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Reged: 08/06/12

Loc: Virginia, USA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5694780 - 02/22/13 01:47 PM

I have a tv-102 manufactured around 2002 and the flocking paper is still very good. No sign of peeling or bubbling. I once thought there was one but it turned out to be under the lens cell bolt, where the inside surface of the tube is not flat.

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Paul G
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Reged: 05/08/03

Loc: Freedonia
Re: Refractor Anti Reflection Coating longevity. new [Re: jrbarnett]
      #5694831 - 02/22/13 02:18 PM

Quote:

"much less scatter than aluminum mirror diagonals (on a molecular level the aluminum coating is quite rough)"

Sadly, this is untrue. Having tested a host of diagonals, including the A-P Maxbright using a precisely spaced green laser and calipers to measure contact spot size on the mirror or prism first surface, even cleaned dielectric diagonals, on average, show larger contact spots (indicating greater surface scatter) than standard aluminum coated and quality prism surfaces. Theory is fine as far as it goes, but when it is accepted as fact without verification it becomes marketing hype.




What you're seeing was discussed some time ago:

Dielectric vs aluminum mirror diagonals

Back to the op, the primary reason to get a dielectric diagonal is the ability to clean it without causing sleeks in the coatings. A little dust on the diagonal mirror surface will have a much greater adverse effect on the image than any difference in reflectivity or scatter. Keep in mind the image occupies the central 1/4 inch or so of the mirror, a little dust that would cause zero degradation in the image if on the objective surface causes noticeable loss of low contrast detail if on the diagonal mirror (as does dust on the surface of an eyepiece where the image is also concentrated in a very small area).

Edit:

Also to the op, mag fluoride has its applications but has drawbacks as well. It would be an especially poor choice for ED glass elements since both the ED glass (including fluorite) and mag-fl are both very low refractive index materials and there wouldn't be enough difference between them to reduce reflections by more than a very small amount. On an appropriate type of high index glass mag-fl at best still leaves about 1.5% reflection, modern multicoatings are in the 0.25% range. Also, mag fluoride's transmission curve isn't flat over the color spectrum.

Edited by Paul G (02/22/13 03:28 PM)


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Eddgie
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Reged: 02/01/06

Re: Refractor Anti Reflection Coating longevity. new [Re: Paul G]
      #5694877 - 02/22/13 02:37 PM

Quote:

Back to the op, the primary reason to get a dielectric diagonal is the ability to clean it without causing sleeks in the coatings. A little dust on the diagonal mirror surface will have a much greater adverse effect on the image than any difference in reflectivity or scatter. Keep in mind the image occupies the central 1/4 inch or so of the mirror, a little dust that would cause zero degradation in the image if on the objective surface causes noticeable loss of low contrast detail if on the diagonal mirror (as does dust on the surface of an eyepiece where the image is also concentrated in a very small area).




I absolutely agree.

Serious planetary observers should buy a good quality dielectric.

For the most serious planetary viewing, the diagonal should be cleaned immediately before use (eyepecies too).

As the light cone converges to the diagonal, the intensity for unit area increases greatly. Dust on the diagonal will indeed scatter this light.

I find cleaning a dirty diagonal makes far more difference in scatter than changing from A T6 Nagler to an Ortho for example. In the latter case, it is hard to see a difference, but if there is dust on the diagonal, it is easy to see the difference in performance.

And this is why people should use dielectric. It is the most robust coating available. it will withstand even sand (silica quartz) abrasion.

Silica Quartz dust is the benchmark because it is hard enough to scratch MgF2 which is the hardest substance that most optics are ever exposed to.

This is why the Military went to Dielectric long ago. Based on my own observations, Marines are excellent shots, but not gentle with optics.

With Dielectrics, they don't need to be. Even desert sand won't scratch dielectrics when wiped with a shirt sleeve.

Hard. Very, very hard.

To be fair, Enhanced Aluminum is quite hard as well. Much harder than most people realize (harder than the glass it is bonded too).

But as far as I know, dielectric is the hardest currently available commercial glass coating technology.


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Paul G]
      #5694915 - 02/22/13 02:56 PM

Hi again Doug,la200o,BCNGreyCat, jrbarnett and Paul G

Thank you ever so much, once again.Lastly I need to seek a answer to this query..this may seem silly and minor,BUT... do the latest new Televue NP-101 Telescopes and their Eyepiece Holders use Rust free Alloy Screws throughout?

I read of Televue having an issue with Rusty Screws which is a pain due to the fact that having to replace Rusty Screws with Stainless Screws is actually quite an expensive endeavour.


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Eddgie]
      #5694945 - 02/22/13 03:11 PM

Hi Eddgie

Thanks. Dielectrics are very tough,yes and there is also the longevity which is a serious positive,supposedly Dielectric Star Diagonals won't (dare I say ever) degrade or oxidise or lose brightness in-a human lifetime.

Secondly Anti Reflection Coatings are Dielectric.

Edited by Plane_Guru (02/22/13 03:12 PM)


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la200o
Carpal Tunnel


Reged: 09/09/08

Loc: SE Michigan, USA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5695186 - 02/22/13 05:10 PM

Quote:

Hi again Doug,la200o,BCNGreyCat, jrbarnett and Paul G

Thank you ever so much, once again.Lastly I need to seek a answer to this query..this may seem silly and minor,BUT... do the latest new Televue NP-101 Telescopes and their Eyepiece Holders use Rust free Alloy Screws throughout?

I read of Televue having an issue with Rusty Screws which is a pain due to the fact that having to replace Rusty Screws with Stainless Screws is actually quite an expensive endeavour.




Dunno the answer to this one, but none of my TV scopes show any sign of such rust, and my 102 is an early one that's been covered with dew, ice, and water from melting ice many times.

Bill


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5695268 - 02/22/13 05:48 PM

I've never read about Televue scopes having rusty screw issues. There are a number of owners on this forum who have Televue scopes and live in maritime climates (in the UK). Perhaps one of them will read this and comment on the reality of the corrosion issue.

Televue scopes have very few exposed screws in actuality, compared to other refractors.

- Jim


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Sean Cunneen
Let Me Think
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Reged: 08/01/07

Loc: Blue Island Illinois
Re: Refractor Anti Reflection Coating longevity. new [Re: jrbarnett]
      #5695325 - 02/22/13 06:15 PM

Certainly the quality of the coating has everything to do with it's longevity, but to give you an example, I have a Brandon Objective from maybe 1946 which has MGF2 coatings in beautiful condition. So when applied correctly and taken care of properly, coatings can last a LONG time.

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azure1961p
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Reged: 01/17/09

Loc: USA
Re: Refractor Anti Reflection Coating longevity. new [Re: Paul G]
      #5695895 - 02/22/13 11:46 PM

I've frankly never heard if refractors *givn it up* like mirror coatings . The ONLY time I've heard if refractors losing coating effectiveness is abrasive contaminants, ammonia , ie; windex and finally dew laden with salt from the sea or outright ocean spray.

Typically tho aside from that - I think they outlast the observer no?

Pete


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: azure1961p]
      #5696280 - 02/23/13 10:17 AM

Hi Paul G

Would you be able to inform what what would be used instead of Magnesium Fluoride for ED glass elements?


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: azure1961p]
      #5696292 - 02/23/13 10:25 AM

True, Pete, and with the exception of the FS-series from Tak, where the coatings on the front fluorite element protect the soft, reactive lens material from environmental or physical damage, failed refractor coatings have minimal impact on the performance of the instrument. I have four or five uncoated refractors that nonetheless perform like champs. Coatings don't fail catastrophically, so a coated objective with coating issues would be only partially uncoated. That would have even less of a detectable impact than having no coatings at all.

Telescopes are tools, and outside tools to boot. Maintaining them and not misusing them is sensible. Obsessing over having them not change in condition at all through time under ordinary use is not. That is better suited to the art collector. Worry about your Vermeer not degrading through the decades, not your Celestron.

Regards,

Jim


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: azure1961p]
      #5696302 - 02/23/13 10:30 AM

Hi Paul,

Would you be able to inform what what would be used instead of Magnesium Fluoride for ED glass elements?


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5696320 - 02/23/13 10:39 AM

Interesting input.I already stated that I love Science and have a keen interest in the Science of Optics.Thanks

Edited by Plane_Guru (02/23/13 11:18 AM)


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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5696342 - 02/23/13 10:51 AM

You may find this informative on mating coating formulations to glass type:

http://tech.groups.yahoo.com/group/ap-ug/message/17280

"For best results of minimum reflectivity, each glass type should have its own
multi-layer formula. This can be expensive, and does impact the final cost in
things like multi-element eyepieces where there may be many different glass
types in each assembly. It is usually cheaper for the manufacturer to coat them
all with the same formula in a large batch. The end result is multi-colored
hues on the various surfaces."

Though it doesn't give you the actual chemical formulation of different coatings that are used for different glass types, it does indicate that different glass types benefit from different coating formulations. This is one of the high-cost features of the ZAO II Orthos - each air to glass surface has multicoatings optimized for the underlying glass type. Almost no one bothers to do this. I don't think that even A-P uses different coating formulations on different surfaces in its refractors.

Now Celestron does share what multicoatings it uses on its SCT corrector plates in this article:

http://www.celestron.com/astronomy/technologies/starbright-xlt/

The correctors are water white glass. Celestron's AR coating on the correctors is a combination of MgF2 and HfO2 (Hafnium Dioxide).

Regards,

Jim


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TG
Pooh-Bah


Reged: 11/02/06

Loc: Latitude 47
Re: Refractor Anti Reflection Coating longevity. new [Re: azure1961p]
      #5698165 - 02/24/13 12:12 PM

Quote:

I've frankly never heard if refractors *givn it up* like mirror coatings . The ONLY time I've heard if refractors losing coating effectiveness is abrasive contaminants, ammonia , ie; windex and finally dew laden with salt from the sea or outright ocean spray.

Typically tho aside from that - I think they outlast the observer no?

Pete




Windex does not contain ammonia:

http://www.aossmedicalsupply.com/doc/msds/glasscleaner.pdf

It's actually quite safe on lens coatings.


Tanveer


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mgwhittle
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Reged: 08/24/11

Loc: Chattanooga, TN
Re: Refractor Anti Reflection Coating longevity. new [Re: TG]
      #5698180 - 02/24/13 12:23 PM

Most windex products do contain ammonia.

From Windex website:

All but two Windex® Glass and Multi-Surface Cleaners contain detergents, solvents, fragrance, Ammonia-D®, and alcohol. They should not be used if ammonia is not recommended for use on surface. (Windex® Multi-Surface Vinegar and Windex® Outdoor Multi-Surface do not contain ammonia. They are safe to use in these cases.)

MSDS on Windex Ammonia D : http://www.btps.ca/files/PDF/MSDS/Windex_Ammonia-D.pdf

Notice there is no mention of "ammonia" in the ingrediants. MSDS are not required to list any component in which there is less than 1% of a hazardous component in the mixture. Ammonia is in there, it's just not a required listing in the MSDS.


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TG
Pooh-Bah


Reged: 11/02/06

Loc: Latitude 47
Re: Refractor Anti Reflection Coating longevity. new [Re: mgwhittle]
      #5699045 - 02/24/13 10:34 PM

Quote:

Most windex products do contain ammonia.

From Windex website:

All but two Windex® Glass and Multi-Surface Cleaners contain detergents, solvents, fragrance, Ammonia-D®, and alcohol. They should not be used if ammonia is not recommended for use on surface. (Windex® Multi-Surface Vinegar and Windex® Outdoor Multi-Surface do not contain ammonia. They are safe to use in these cases.)

MSDS on Windex Ammonia D : http://www.btps.ca/files/PDF/MSDS/Windex_Ammonia-D.pdf

Notice there is no mention of "ammonia" in the ingrediants. MSDS are not required to list any component in which there is less than 1% of a hazardous component in the mixture. Ammonia is in there, it's just not a required listing in the MSDS.




Do you have a source for confirming that there is actually ammonia in there? From what I recall, Ammonia-D is not actually ammonia but marketingspeak for some other chemical.

Tanveer


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teelgul
sage


Reged: 09/02/11

Loc: Australia
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5699170 - 02/25/13 12:20 AM

Televue is a great scope optically and mechanically .
its only weak points if at all are its internal coating and its non airline portability . Its mechanical design is a mixture of old and traditional, but solid. But I dont believe that it can do things which no other 4 inch can do.
if we are a bit flexible with the 4 inch definition then TEC 110 will be way ahead in design,and portability with the same optical performance if not better.
Any way if you live in CON USA internal coatings should not be a worry as its a shorter distance to the Televue factory.
For me the coating peeeling off in 4 places with in three months in the not so humid sydney was a bad experience.
if i were a Televue owner i would be more concerned with the paper coating and a some times loose rack mechanism than with the lens coating which iam sure will outlive all of us. This is from first hand experience of two televue scopes.Hope Televue has a better resin and if the paper coating now is half as durable as their lens coating it will be fine for a life time .


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: teelgul]
      #5699249 - 02/25/13 02:27 AM

Hello teelgul ,

I reside in Queensland,Eastern Australia and I am also worried about the Televue NP-101 Internal Flocking Paper lifespan and durability because where I reside the Weather can also be very humid(Central Queensland).

I have a brand NEW Televue NP-101 on order from:

http://www.bintel.com.au/Telescopes/Refractor/TeleVue-NP101/136/productview.aspx



I phoned The Binocular and Telescope Shop and raised the issue of the Internal Flocking Paper de-flocking and I was told that Televue have changed their Adhesives now to try and combat this very rare? issue.

All my best

Edited by Plane_Guru (02/25/13 05:19 AM)


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teelgul
sage


Reged: 09/02/11

Loc: Australia
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5699306 - 02/25/13 04:47 AM

Hello guru
Televue did fix it up for me but i had to pay one way fare.
If the new resin has fixed it up then great. Televue should have done this long
Back .A slight debonding may not performance but it should not happen in a scope of this price range. . Any way if you are going to use it from a fixed location with occasional transport then it should be fine .
Cheers


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Plane_Guru
member


Reged: 02/17/13

Re: Refractor Anti Reflection Coating longevity. new [Re: teelgul]
      #5699316 - 02/25/13 05:24 AM

Quote:

Hello guru
Televue did fix it up for me but i had to pay one way fare.
If the new resin has fixed it up then great. Televue should have done this long
Back .A slight debonding may not performance but it should not happen in a scope of this price range. . Any way if you are going to use it from a fixed location with occasional transport then it should be fine .
Cheers





Hi ,I concur wholeheartedly..The Flocking paper De-Flocking and becoming unglued should never be an issue in a Premium Telescope of this price .I too hope that Televue's change to a new Adhesive/Resin fixes the De-Flocking issue.


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mgwhittle
Pooh-Bah
*****

Reged: 08/24/11

Loc: Chattanooga, TN
Re: Refractor Anti Reflection Coating longevity. new [Re: TG]
      #5699425 - 02/25/13 08:49 AM

Quote:

Quote:

Most windex products do contain ammonia.

From Windex website:

All but two Windex® Glass and Multi-Surface Cleaners contain detergents, solvents, fragrance, Ammonia-D®, and alcohol. They should not be used if ammonia is not recommended for use on surface. (Windex® Multi-Surface Vinegar and Windex® Outdoor Multi-Surface do not contain ammonia. They are safe to use in these cases.)

MSDS on Windex Ammonia D : http://www.btps.ca/files/PDF/MSDS/Windex_Ammonia-D.pdf

Notice there is no mention of "ammonia" in the ingrediants. MSDS are not required to list any component in which there is less than 1% of a hazardous component in the mixture. Ammonia is in there, it's just not a required listing in the MSDS.




Do you have a source for confirming that there is actually ammonia in there? From what I recall, Ammonia-D is not actually ammonia but marketingspeak for some other chemical.

Tanveer




Hi Tanveer, the quote above is directly from Windex's website regarding ammonia in their products. As you see they say specifically, except for two products, all their glass cleaners contain ammonia.

Here are all the ingredients in Windex with Ammonia D:
http://www.whatsinsidescjohnson.com/en-us/products-by-brand/windex-1/windex-w...

And the contents of original Windex (the stuff often recommended here):
http://www.whatsinsidescjohnson.com/en-us/products-by-brand/windex-1/windex-o...

Ammonium Hydroxide is listed in both.

I used the MSDS from Ammonia-D as an example that some ingredients are not listed on the MSDS even though they are in there. Ammonia-D is a trademarked marketing name and it is a 28% solution of ammonia present at .05% in their cleaners. Since it is only at .05% it is not required to be listed on the MSDS. You can gleen this information from the Windex website (http://www.windex.com/en-US/Pages/Faq.aspx ), and how to read an MSDS (many sites, this just happened to come up first on a google search http://www.ehso.com/msds_regulations.php )


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5699593 - 02/25/13 10:29 AM

I've seen few Televue refractors, including recent vintage units, on which you could see at least a bubble or two and/or the seam in the tube flocking material. Most never come loose, but some do. On Astromart you will see pictures from time to time of Televue objectives with the corner of the flocking material drooping into the tube. It happens.

That said, it shouldn't be a big deal as Televue will repair the issue in the unlikely event that that it arises. It's a risk (decontacted flocking) assumed to achieve the tube diameter goals (smaller due to the lack of knife edge baffles). In all things there are tradeoffs. Talahashi paint, for example, is beautiful but thin and fragile as a coating of toothpaste. Televue tube paint is bombproof by comparison. In all things there are tradeoffs. No one is charging enough for any of these scopes to be able to deliver perfection in every case. That's why we have warranties.

Regards,

Jim


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teelgul
sage


Reged: 09/02/11

Loc: Australia
Re: Refractor Anti Reflection Coating longevity. new [Re: Plane_Guru]
      #5699817 - 02/25/13 12:57 PM

Hello guru
Just make sure about warranty in case .I did not get worried much about the issue And got upset only when televue initially advised me that it was due to humidity and not normally warrantied .


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TG
Pooh-Bah


Reged: 11/02/06

Loc: Latitude 47
Re: Refractor Anti Reflection Coating longevity. new [Re: mgwhittle]
      #5700165 - 02/25/13 04:20 PM

Quote:

Quote:

Quote:

Most windex products do contain ammonia.

From Windex website:

All but two Windex® Glass and Multi-Surface Cleaners contain detergents, solvents, fragrance, Ammonia-D®, and alcohol. They should not be used if ammonia is not recommended for use on surface. (Windex® Multi-Surface Vinegar and Windex® Outdoor Multi-Surface do not contain ammonia. They are safe to use in these cases.)

MSDS on Windex Ammonia D : http://www.btps.ca/files/PDF/MSDS/Windex_Ammonia-D.pdf

Notice there is no mention of "ammonia" in the ingrediants. MSDS are not required to list any component in which there is less than 1% of a hazardous component in the mixture. Ammonia is in there, it's just not a required listing in the MSDS.




Do you have a source for confirming that there is actually ammonia in there? From what I recall, Ammonia-D is not actually ammonia but marketingspeak for some other chemical.

Tanveer




Hi Tanveer, the quote above is directly from Windex's website regarding ammonia in their products. As you see they say specifically, except for two products, all their glass cleaners contain ammonia.

Here are all the ingredients in Windex with Ammonia D:
http://www.whatsinsidescjohnson.com/en-us/products-by-brand/windex-1/windex-w...

And the contents of original Windex (the stuff often recommended here):
http://www.whatsinsidescjohnson.com/en-us/products-by-brand/windex-1/windex-o...

Ammonium Hydroxide is listed in both.

I used the MSDS from Ammonia-D as an example that some ingredients are not listed on the MSDS even though they are in there. Ammonia-D is a trademarked marketing name and it is a 28% solution of ammonia present at .05% in their cleaners. Since it is only at .05% it is not required to be listed on the MSDS. You can gleen this information from the Windex website (http://www.windex.com/en-US/Pages/Faq.aspx ), and how to read an MSDS (many sites, this just happened to come up first on a google search http://www.ehso.com/msds_regulations.php )




Thanks, this is interesting reading. However, with a pH of 10.4, I don't think that Windex is going to strip any fluoride coatings off any time soon.

Tanveer.


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mgwhittle
Pooh-Bah
*****

Reged: 08/24/11

Loc: Chattanooga, TN
Re: Refractor Anti Reflection Coating longevity. new [Re: TG]
      #5700230 - 02/25/13 04:52 PM

I completely agree with you. I have used Windex, along with other products (ROR, isopropyl alcohol and acetone) for years and will continue to do so.

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