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Nikon ED82 Frontlens coating maybe corrupted (1 Viewer)

Odradek

Well-known member
Hi,

i have a question regarding the coating of my ED82´s frontlens. With the time i see there are more and more little bright dots in the coating. I dont clean the lens that often, and when necessary only with microfibre cloth and carefully. But it seems that their number increase. Maybe 2 years ago there where only 2-3 and now there are maybe 30 dots already. They are tiny, the biggest maybe 0,5mm. But i am afraid the coating is corrupted and will brittle off sooner or later.

Has any other ED82 owner experienced anything like this (not the brittle but the dots)?
 
Hi,

are you sure that these are not just specks from drops of water that have evaporated and left some dirt on there? Even 20-30 of those on the objective lens are probably not visible, so no hurry to clean. If you do, Baader optical wonder is a very good idea.

Usually optical coatings are not brittle and flake off - they can be damaged by frequent and improper cleaning - this is like polishing or even grinding them off or by chemical reactions (remember the early Leica Televid disaster).

Can you post images?

Joachim
 
Thank you for your answer!

Its not that easy to make a picture from those spots. I will try it again tomorrow. But they are nothing more than little shiny dots. I have used optical wonder from baader already. But i cant get rid of them anyways. Thats why i think it has something to do with "holes" in the coating.

I wonder whats the reason for these holes.
 
...Has any other ED82 owner experienced anything like this (not the brittle but the dots)?

I've not seen this on my ED82 or any of my Nikon Fielscopes, even after decades of use.

Like jring says, are you sure these are coating flaws, and not just residues?

If you are only using a microfiber cloth to clean, you are accumulating resides that won't come off when dry.
Try using distilled water (or better, regular lens cleaning fluid containing ethanol) on a natural cotton ball to get the glass really wet and dissolve residues.
Use another cotton ball or two (or your microfiber cloth, but only if it is perfectly clean) to dry the lens, then check to see if the dots are still there and report back here.

--AP

You replied while I was writing the above. If you've already used a wet method, perhaps they are coating flaws. I use V-vax ROR to clean lenses when nothing else works.
 
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Its not possible to get all of them at once on the photo. But the image should be good enough to get an idea of how it looks. I tried to dissolve them with more cleaning fluid on the cloth (dont have cotton pads at the moment). But it had no further effect.
 

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Hi,

if the spots can't be removed with a liberal dose of optical wonder and some gentle rubbing with a cotton pad or microfiber cloth, they might indeed be coating damage. The question remains, what causes them?

Have you used the scope near salt water or in other situations where drops of chemicals might have gotten on the lens?
Can you try to watch the spots with a magnifier to rule out fungus on the inside of the lens?
Or maybe paint flakes that got loose somewhere on the inside and now sticking to the front element - do the positions of the spots change over time?

Is the scope still under warranty - if yes, then it might be a good idea to ask Nikon about this.

In the current state I'm quite sure there will be no visible degradation of the image, so other than resale value there is no problem. But of course one should try to find the cause in order to prevent the appearance of further dots.

Joachim
 
Its not possible to get all of them at once on the photo. But the image should be good enough to get an idea of how it looks. I tried to dissolve them with more cleaning fluid on the cloth (dont have cotton pads at the moment). But it had no further effect.

These spots don't look like damage to the coatings to me. Coating damage (other than that caused by improper cleaning) usually looks like the coatings are sort of flaking of.

I don't know the Baader stuff you used. Try a mixture of isopropanol+purefied water instead (Isopropanol+destilliertes Wasser aus der Apotheke, Mischungsverhältnis 1:1). Use a clean microfibre cloth - wash it carefully and make sure you get all the soap out before using it. Don't use too much fluid so it doesn't get into the seals around the lens. Dry the lens with a second, clean microfibre cloth.

BTW, I've never seen any damage to the coatings of any of the Nikon Fieldscopes. They seem to be pretty tough.

Hermann
 
Thank you again!

I havent used the scope near saltwater or chemicals. But thats a plausible explanation that small drops maybe etched the coating. At least they are not from inside and dont move either.
Watching them under a magnifying glass might give a better impression. I will try this.

Hermann, thats the fluid i used ...

http://www.baader-planetarium.com/d...tel/optical-wonder-reinigungsflüssigkeit.html

So far i think it wont change the optical quality. But as the number increased i am afraid this might change when there are more of these dots.
 
Looks like some kind of solvent. I don't particularly like using such stuff without knowing what it is. Using a mixture of isopronanol and purefied water, like I suggested, has the advantage of dissolving some dirt that can't easily be got rid of using pure alcohol, some petrol based solvent and the like.

Hermann
 
I zoomed in using Photoshop and it appears there's a spot off the right side of the lens. Did something splatter on the scope? My eyeglasses got hit with some mosquito repellent that was a devil to remove. A mix of alcohol, water and a few drops of soap did the job after several careful cleanings. Just a thought.

What are the white specks?
 
I will try the mixture you suggestet, thank you!

The white specks are the dots i mean. They are that white because of the reflecting light. From different angles they are sometimes more, sometimes less visible. The faded dots in the background are the same, just not so bright because of a different angle.
 
I recommend taking the scope to a qualified camera repair shop for cleaning and evaluation. They will know exactly which chemicals to use and will use them prudently. They will also be able to tell you if it is a coating flaw. Using acetone for instance is something I would not do myself, but I have understood technicians who know what they are doing use it for lens cleaning also. Not everything comes off with soap, water and alcohol.

Kimmo
 
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