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Old Coatings (1 Viewer)
- Thread starter Rg548
- Start date
Orion optics U.K. have coating facilities either normal or enhanced.
So do other companies.
But the cost may be more than the binocular is worth.
However, if a Leica BA is still under 30 year warranty it may be that Leica can do something about this.
The life of mirror coatings varies.
I had two Nikon 500mm f/5 reflex lenses.
The better optical performer had coating that was failing.
The lesser optical performer had excellent coatings.
With mirror optics, some quite old examples are O.K. with others the coatings are almost gone.
My 20.5 inch Newtonian was stored at the back of my garage.
Within a week from new the coating was gone.
The car exhaust had stripped the aluminium coating.
The main mirror had to be realuminised and I put the car in forwards and left the garage door open for a while.
An AE optics 6 inch f/8 Newtonian that I bought for £40 had unbelievably good optics but the mirror coatings were almost gone and needed replacement.
Some Tamron mirror lenses have extra protection layers and most mirror lenses probably are overcoated for long life.
Ordinary mirrors can last a long time, but my bathroom mirror is stained at the bottom but fine otherwise.
The Amplivid 6x24 would benefit from modern coatings on the mirror prisms.
Regards,
B.
So do other companies.
But the cost may be more than the binocular is worth.
However, if a Leica BA is still under 30 year warranty it may be that Leica can do something about this.
The life of mirror coatings varies.
I had two Nikon 500mm f/5 reflex lenses.
The better optical performer had coating that was failing.
The lesser optical performer had excellent coatings.
With mirror optics, some quite old examples are O.K. with others the coatings are almost gone.
My 20.5 inch Newtonian was stored at the back of my garage.
Within a week from new the coating was gone.
The car exhaust had stripped the aluminium coating.
The main mirror had to be realuminised and I put the car in forwards and left the garage door open for a while.
An AE optics 6 inch f/8 Newtonian that I bought for £40 had unbelievably good optics but the mirror coatings were almost gone and needed replacement.
Some Tamron mirror lenses have extra protection layers and most mirror lenses probably are overcoated for long life.
Ordinary mirrors can last a long time, but my bathroom mirror is stained at the bottom but fine otherwise.
The Amplivid 6x24 would benefit from modern coatings on the mirror prisms.
Regards,
B.
Thanks...I've said before I really like some older stuff, particularly Leica BA's or BN's, even though they are not optically as good as modern stuff.
It's nostalga.... but I have been worried about stories of coatings failing, and wondered wether in time they could be re-done.
It's nostalga.... but I have been worried about stories of coatings failing, and wondered wether in time they could be re-done.
tenex
reality-based
Our BN is over 20 years old and has no problem. But if you did, Leica would repair it, surely by replacing the prisms rather than re-coating them. (The replacements might be a few years newer or not, raising the question why they haven't also deteriorated, as most other people's haven't, but that does seem to be the case.)
Horace Dall would... just kidding!
From what I gather, if it happens to you, you'd better hope Leica has a spare prism cluster(s) left in their inventory. It may be possible in theory to have the reflecting surface in a Schmidt-Pechan re-coated, but the cost of doing so would be prohibitive.
I expect this to happen to my Zeiss Dialyt at some point, hopefully not before I'm too decrepit for it to matter!
Going off topic I know, but it would be interesting to find out how practical multi-coating single-coated or uncoated binoculars might be. Would you need different coatings for each binocular model based on what it was already coated with? There are enough old binoculars out there (eg. old Zeiss and other historic models with uncoated lenses) that someone probably could put together a large enough batch of lenses/prisms to justify the expense. I'd be intrigued to see how something like say a Mk 41 would perform with modern coatings. I think I saw a photo of a Sard 6x42 at a PRC binocular owners' gathering that looked as though it might have been re-coated. Maybe the owner was well heeled and connected enough to get Kunming or a similar firm to take on that project.
From what I gather, if it happens to you, you'd better hope Leica has a spare prism cluster(s) left in their inventory. It may be possible in theory to have the reflecting surface in a Schmidt-Pechan re-coated, but the cost of doing so would be prohibitive.
I expect this to happen to my Zeiss Dialyt at some point, hopefully not before I'm too decrepit for it to matter!
Going off topic I know, but it would be interesting to find out how practical multi-coating single-coated or uncoated binoculars might be. Would you need different coatings for each binocular model based on what it was already coated with? There are enough old binoculars out there (eg. old Zeiss and other historic models with uncoated lenses) that someone probably could put together a large enough batch of lenses/prisms to justify the expense. I'd be intrigued to see how something like say a Mk 41 would perform with modern coatings. I think I saw a photo of a Sard 6x42 at a PRC binocular owners' gathering that looked as though it might have been re-coated. Maybe the owner was well heeled and connected enough to get Kunming or a similar firm to take on that project.
Last edited:
Binocollector
Well-known member
Re. Post #6.
Contact Kingsview Optical, Rye if you seriously want any optical component made or coated.
With old binoculars there may be a problem as the single coating may be uneven or faulty.
In actual fact the prescription may be sent to a Chinese specialist and the finished product sent back maybe quickly.
Or it could be made in the UK.
With the problem in the Nikon thread with the 10x42 SE.
The three curves must be accurately measured, optical glass types identified, thickness accurately measured as well as diameter.
This would be most easily done by sending the successfully cemented group and the broken group to Kingsview.
One could discuss on the phone whether it is cost effective.
One could also deal directly with China, but personally I'd contact Kingsview.
But any mistake in measurement is down to the owner of the optics if the measurements are done at home.
This is not as difficult as some here may believe.
Custom optics are often made for scientific research.
The very best optics are hand made by the few master opticians still around.
These may be needed for laser work.
Regards,
B.
Contact Kingsview Optical, Rye if you seriously want any optical component made or coated.
With old binoculars there may be a problem as the single coating may be uneven or faulty.
In actual fact the prescription may be sent to a Chinese specialist and the finished product sent back maybe quickly.
Or it could be made in the UK.
With the problem in the Nikon thread with the 10x42 SE.
The three curves must be accurately measured, optical glass types identified, thickness accurately measured as well as diameter.
This would be most easily done by sending the successfully cemented group and the broken group to Kingsview.
One could discuss on the phone whether it is cost effective.
One could also deal directly with China, but personally I'd contact Kingsview.
But any mistake in measurement is down to the owner of the optics if the measurements are done at home.
This is not as difficult as some here may believe.
Custom optics are often made for scientific research.
The very best optics are hand made by the few master opticians still around.
These may be needed for laser work.
Regards,
B.
The glass types, curves and thicknesses may be stated in an original patent for the Nikon SE.
But I would actually measure them as the patent may deliberately be slightly non optimal.
In actual production there are tolerances that have to be adhered to, although an occasional lemon might be made.
With regard to going to optical specialists it should be for those who seriously want to pay for this work.
Regards,
B.
But I would actually measure them as the patent may deliberately be slightly non optimal.
In actual production there are tolerances that have to be adhered to, although an occasional lemon might be made.
With regard to going to optical specialists it should be for those who seriously want to pay for this work.
Regards,
B.
lilcrazy2
Well-known member
I've heard of this too, but have never known anyone that has had this problem happen to a bin they owned, nor have I had it happen to any of the dozens and dozens of binos I own or have owned. One would think that oxidation would be impossible in any waterproof sealed bino, unless the nitrogen/argon has leaked out, allowing in oxygen. I would imagine you could buy 2 or 3 BA replacements for the cost of the entire process to have any binos coatings renewed, unless done under factory warranty.
Silver coatings means the backside of the prism which works like a mirror, not the lenses. They're going for maximum reflection of the light, not passing light through like lens coatings. Silver coatings deteriorate over time, I think it's due to oxidation. So inside a purged and sealed bino I would expect the silver coating to last indefinitely, unlike telescope mirrors which are open to the outside air.
I owned my Nikon HG's until 13 or 14 years after manufacture, and I didn't see any brightness drop-off compared to new binos, so it looks like the silver was holding up just fine. FWIW, dielectric coatings were developed in part for durability and are supposed to last forever on a mirror surface, even in open air. The reflectivity can be 99% so that's why everybody's switched to dielectric.
I owned my Nikon HG's until 13 or 14 years after manufacture, and I didn't see any brightness drop-off compared to new binos, so it looks like the silver was holding up just fine. FWIW, dielectric coatings were developed in part for durability and are supposed to last forever on a mirror surface, even in open air. The reflectivity can be 99% so that's why everybody's switched to dielectric.
cytherian
Active member
I apologize upfront for not being very knowledgeable about this subject, but it is of fascination to me not only from a durability aspect but also from a technological one.
What's the earliest point in time where dielectric coatings have been used on lenses for optics, such as binoculars? Is the general consensus that it's preferable to have a dielectric coating for any mid-tier on up binoculars?
Are there certain coatings (such as silver) used in higher end binoculars years ago that are known to have a limited shelf life, independent of exposure to elements? I've been wondering if a pristine set of 15 year old alpha-level binoculars could be like a "ticking time bomb," where the lenses are optically perfect but that due to age, subsequent exposure to bright light might trigger deterioration in a relatively short time frame. Or should that not be of any concern?
What's the earliest point in time where dielectric coatings have been used on lenses for optics, such as binoculars? Is the general consensus that it's preferable to have a dielectric coating for any mid-tier on up binoculars?
Are there certain coatings (such as silver) used in higher end binoculars years ago that are known to have a limited shelf life, independent of exposure to elements? I've been wondering if a pristine set of 15 year old alpha-level binoculars could be like a "ticking time bomb," where the lenses are optically perfect but that due to age, subsequent exposure to bright light might trigger deterioration in a relatively short time frame. Or should that not be of any concern?
Dielectric coatings are used on prisms (Schmidt-Pechan), not lenses.
You may want to double check this (buyer beware etc), but if your alphas/former alphas are 15 years old ie. from 2007, the top models of the time would have all had dielectric coated prisms (where needed) by then.
You may want to double check this (buyer beware etc), but if your alphas/former alphas are 15 years old ie. from 2007, the top models of the time would have all had dielectric coated prisms (where needed) by then.
lilcrazy2
Well-known member
here is a link that may help you understand coatings and prisms a little better
Binocular Lens And Prism Coatings - Important Facts in 2022
When using binoculars, the quality of the image depends on several factors, including the types of binocular lens and prism coatings placed on...
birdsatfirstsight.com
