Hoya Filter Coating Failure—Follow up

In preparation for a trip to Iceland next month, I inspected my filters and discovered that both of my Hoya filters (a 10 stop and 6 stop ND) have weird specking and deterioration of the coatings. I had returned one filter a couple of years ago because I became all blotchy despite rarely being used and being stored securely in a filter pouch.

I’m wondering whether others have had problems with Hoya. I have a B+W filter (cpl) that has been stored in the same pouch, same conditions, and used marginally more often that has never had an issue (after 8 years of use).

Have you had Hoya coating failures?
Do you store filters in a pouch? Could off-gassing from the fabric create these issues?


I have numerous Hoya filters and I just took a look at them. They all look normal. I store them all in filter wallets. Could you have used a cleaner on them that is not coating-friendly? That is all I can think off, unless Hoya had some kind of weird manufacturing problem. You might call their customer service dept. and ask about it. Who knows, maybe they will send you free replacements.

Thanks, Harley. I wonder if they have some bad lots now and then. This is three for three with Hoya filters getting weird speckles. I never use any cleaners, just clean rocket blower and freshly rinsed breath.

The filters had just a one year warranty, but I’ll contact them anyway in case there was the equivalent of a recall and they are feeling generous. Thanks for the suggestion @Harley_Goldman. I just ordered on B+W 6 stop since I’m 2 for 2 with no problems there. The filter wallet doesn’t see to affect what they use, and i only use these things every few years, so I don’t want another surprise when I pull it out of the wallet.


I used to see exactly that in quite a number of filters from all brands. Then I discovered the fine invisible mist drifting around when I applied Backwoods Off with its 30% DEET content. It was eating my filter (and lens) coatings like crazy, in addition to melting plastic. Switched to insecticides with picaridin and haven’t had an incident since. It’s been well established in Europe for a couple of decades and used by their armed forces, and in my use has proven as effective as DEET.

Dunno if you were using a DEET aerosol around those filters, but the results sound just like mine.

No aerosols for me—mostly desert shooting, so few bugs, and very little use at all, so I don’t think I can blame it on sand or salt either.

Good consideration though. That’s why I rinse with water before breathing on a lens…who know what’s in my toothpaste or how acidic my coffee breath is!!


Sounds as though you’re even more careful than we are. I’ve run out of ideas outside the Hoya factory.

Does what your discussing have any effect on the function of the filter whatsoever?

Good question Steve. I haven’t tested the impact on an image. One filter has two big ‘holes’ in the coating, and the other is speckled throughout but with very fine light leakage and might work (built in dodge perhaps?)

I contacted Hoya and they did invite me to send them back despite being past the one year warranty. They were very helpful last time so maybe I’ll get replacements.


If you use lens hoods or otherwise keep direct light off the filter, you might have trouble discerning any effects. But let sunlight hit the filter directly and unusual things can happen. Same for lenses with damaged coatings.

Follow up: Hoya replaced the two filters at no charge despite the warranty period. Apparently they no longer produce the same filters and now offer an IRND instead. The info says it is not coated, so the darkening is part of the glass itself?

I’m eager to try it out later today. Glad too that they replaced them “as a courtesy.”

Certainly the sign of a responsible company, isn’t it?

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