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Custom applying of multi-coating
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PostPosted: Tue Mar 14, 2017 10:45 pm    Post subject: Custom applying of multi-coating Reply with quote

Has anybody ever done a multi-coating of any camera lens after it's production, by taking it to a specialized shop for that kind of job? One day I was sitting and looking at my prescription glasses which were expensive and have cool emerald colored reflection, which are 10% of the brightness of another glasses which had no coating. I saw the same green reflection on my cheap Nikon lens, but never saw such coatings on old MF lenses, so I was wondering if that could be done, to maybe enhance already good lenses?


PostPosted: Wed Mar 15, 2017 6:05 am    Post subject: Reply with quote

I doubt you can do this at home. These processes are industrial scale and work on unassembled glass, and certainly would not be economical even if you could do them.

Plus I think a lensmaker has to tune the optical formula for these too, and doing it in your workshop you would probably immortalize any dirt, etc etc

What you can easily do is take black paper and build a lens hood for them.


PostPosted: Wed Mar 15, 2017 6:27 am    Post subject: Reply with quote

if you really want to coat lens i know a nice person in kiev who know a nice person who do that Wink


PostPosted: Wed Mar 15, 2017 7:45 am    Post subject: Re: Custom applying of multi-coating Reply with quote

AlexKV wrote:
Has anybody ever done a multi-coating of any camera lens after it's production, by taking it to a specialized shop for that kind of job? One day I was sitting and looking at my prescription glasses which were expensive and have cool emerald colored reflection, which are 10% of the brightness of another glasses which had no coating. I saw the same green reflection on my cheap Nikon lens, but never saw such coatings on old MF lenses, so I was wondering if that could be done, to maybe enhance already good lenses?


Cost is usually several hundred $ just for one lens element. And there is always risk that it gets damaged. Plus cost of taking the lens apart and later reassemble it correctly. I WOULD CERTAINLY NOT DO THAT.


PostPosted: Wed Mar 15, 2017 8:35 am    Post subject: Reply with quote

This also interests me for a while. Usually only front elements gets priority thus little disassemble effort. There should be some cheap way considering 5 EUR glasses being sold in post office has it applied.


PostPosted: Wed Mar 15, 2017 1:04 pm    Post subject: Reply with quote

Hmm, I wonder what the request would be: "I have some chromatic aberration in the 620nm zone so be sure that the coating thickness will be exactly 1/4 of that."


PostPosted: Wed Mar 15, 2017 1:09 pm    Post subject: Re: Custom applying of multi-coating Reply with quote

AlexKV wrote:
Has anybody ever done a multi-coating of any camera lens after it's production, by taking it to a specialized shop for that kind of job?

Interesting question.

kds315* wrote:
Cost is usually several hundred $ just for one lens element. And there is always risk that it gets damaged. Plus cost of taking the lens apart and later reassemble it correctly. I WOULD CERTAINLY NOT DO THAT.

Thirty years ago, here in Switzerland, it was possible to coat old lenses. I simply would have to bring the lens to my photo dealer who in turn sent it to a specialized workshop. polishing and re-coating would be CHF 80.-- per lens, at that time maybe 40 USD.

Probably that kind of service doesn't exist any more, but probably one could find here someone to do it even today.

Stephan


PostPosted: Wed Mar 15, 2017 2:49 pm    Post subject: Re: Custom applying of multi-coating Reply with quote

stevemark wrote:
AlexKV wrote:
Has anybody ever done a multi-coating of any camera lens after it's production, by taking it to a specialized shop for that kind of job?

Interesting question.

kds315* wrote:
Cost is usually several hundred $ just for one lens element. And there is always risk that it gets damaged. Plus cost of taking the lens apart and later reassemble it correctly. I WOULD CERTAINLY NOT DO THAT.

Thirty years ago, here in Switzerland, it was possible to coat old lenses. I simply would have to bring the lens to my photo dealer who in turn sent it to a specialized workshop. polishing and re-coating would be CHF 80.-- per lens, at that time maybe 40 USD.

Probably that kind of service doesn't exist any more, but probably one could find here someone to do it even today.

Stephan


That service has gotten rare, but still exists, but rather pricey!


PostPosted: Wed Mar 15, 2017 4:52 pm    Post subject: Reply with quote

thebbm wrote:
if you really want to coat lens i know a nice person in kiev who know a nice person who do that Wink


Araxfoto in Kiev used to do that relatively cheap (less than 100$/lens). I've asked them ~2 years ago if they still do it, but the answer was "no, the factory sold the coating machine". If there is somebody else with a coating machine in Kiev it would be interesting to know.
Could you ask him for the price he is asking?
All the other coating services I could find at that time were either very expensive (several hundred dollars/lens) or they were industrial (cheap, but only accepting orders in the range of hundreds of lenses).


PostPosted: Wed Mar 15, 2017 5:47 pm    Post subject: Reply with quote

@dan_ if i remember well it is around the 30euros for the coating + the shipping. he also repare lenses


PostPosted: Wed Mar 15, 2017 7:46 pm    Post subject: Reply with quote

I am quite curious about this. It might make sense for certain older lenses (rare, expensive with damaged coatings) or as an experiment on lenses that didn't have coatings when manufactured.


PostPosted: Wed Mar 15, 2017 8:57 pm    Post subject: Reply with quote

I can do it for $300. You choose the color!



PostPosted: Thu Mar 16, 2017 6:45 am    Post subject: Reply with quote

dan_ wrote:
thebbm wrote:
if you really want to coat lens i know a nice person in kiev who know a nice person who do that Wink


Araxfoto in Kiev used to do that relatively cheap (less than 100$/lens). I've asked them ~2 years ago if they still do it, but the answer was "no, the factory sold the coating machine". If there is somebody else with a coating machine in Kiev it would be interesting to know.
Could you ask him for the price he is asking?
All the other coating services I could find at that time were either very expensive (several hundred dollars/lens) or they were industrial (cheap, but only accepting orders in the range of hundreds of lenses).


They don't do it anymore I read somewhere...

Seen? Click here to see on Ebay


PostPosted: Thu Mar 16, 2017 2:07 pm    Post subject: Reply with quote

No it is very difficult a process. In my country I had found a small lab in Milan who does this service for telescopes, after some long search. 30 euros per lens. Not only, lens had to be stripped and they didn't know how to do a stripping of the old coat: another telescope servicing lab told me to use nitric acid as suggested by internet sources. I tried it and the lens dissolved, it was probably plastic.

So if you want to coat a never coated lens yes you may try at some telescope making small lab. But if you need to re-coat an already coated lens you shall better know that there is no magic bullet, you will have to experiment with nitric acid dilutions (it is said to be a week long stripping or so).

And make sure you are stripping only glass lenses, mine was the front of a sixties yashinon DX and quickly dissolved ...

I found nitric acid on the italian amazon site.


PostPosted: Thu Mar 16, 2017 7:15 pm    Post subject: Reply with quote

thebbm wrote:
@dan_ if i remember well it is around the 30euros for the coating + the shipping. he also repare lenses

Thanks, it's good to know!

kds315* wrote:
Seen? Click here to see on Ebay

Thanks for the link, Klaus. I haven't seen it before.

-bghomofaber-
Interesting! I never thought at telescopes service labs... Smile


PostPosted: Thu Mar 16, 2017 8:09 pm    Post subject: Reply with quote

There are many suppliers in the US who do coating. I work for a laser company and am aware of a bunch. It requires special equipment (coating chamber) and is usually charged per run, so it would not be worth doing for just 1 or 2 elements. That and you'd want to know what coating curve you want - there are many possibilies.

That being said, these places have coating abilities:
-OptoSigma (Japanese, but I know they have a whole specific coating shop in California)
-Edmund Optics (NY)
-ThorLabs (NJ)
-REO Optics (CO)


PostPosted: Fri Mar 17, 2017 6:58 pm    Post subject: Reply with quote

In the UK, I think the well-known Leica repairer and restorer Malcolm Taylor (Upper Lye Farm, Aymestrey, Leominster, Herefordshire, HR6 9SZ UK Tel 01568 770542) is still able to do recoating, although I don't know whether he can do multi-layer coatings. He has no website or published email address but in my experience is very helpful if you telephone him and he has a reputation for doing good work. He isn't cheap but the lenses he serviced for me last year were done well and sent back quickly. Might be worth trying if anyone has a top class lens that needs restoring.


PostPosted: Fri Mar 17, 2017 7:36 pm    Post subject: Reply with quote

I've heard Vasiline makes an interesting coating. Laughing

Seriously, there is a spray-can product. Just lay bare element on old newspaper & spray on coating. Each coat adds x microns -- calculate beforehand how many coats are needed to produce coatings for wavelengths desired. Multiple coatings are separated by a special sealing coat. Just kidding. Sad

How about local University lab? I once got some quartz crystal matrix that had been in chamber used to prepare specimens for electronic scanning microscope -- coated it with 1-atom thick of purest gold, making crystal a beautiful blue color(!).


PostPosted: Fri Mar 17, 2017 7:45 pm    Post subject: Reply with quote

The where to get coatings question has been answered in several threads here at MFlenses! Search...

Iirc our HK friends know of places, some on the main land.

I wonder, for example, if somebody like Edmund Scientific Company would accept a batch of lens elements from MFlense members; as many elements as will fit in chamber -- cost savings... That, of course, will work only if machine will different element sizes at once...I'm not sure.


PostPosted: Mon Mar 20, 2017 6:11 am    Post subject: Reply with quote

I specify optical filters as part of my job, so I specify coatings as well.
Because of this I know a bunch of coating companys, but mainly those for higher volume.
There it is usual to make special jigs to have the glass on it, so this is not possible for our needs with many different sizes. Dont know how jigs with variable diameter would look like, and how few lenses it could hold on one coating run.

Most companies have a Broad-Band Anti-Reflection (BBAR) like coating for visual transmission. But without knowing the material of the glass it could be quite risky.