Is this Fungus? Need Expert Opinion

Alec246 said:

The Nikon 28mm AI-S is one of my dream lenses. Hard to find, specially in great shape, and expensive when you do.

Found one at MPB, received it, but when I flashed a lightbeam, I was sure I spotted fungus. I could see a white mark with what appeared to be an organic spiderweb structure. But I didnt have a gear to take a good photo to better analyse.

Few days later, I got the camera on a tripod, and it's not a macro lens, but I carefully focused as best as I could, in nearest focus, and these are the photos I would appreciate being analysed.

Now I am not so sure if it's indeed Fungus? What looked like the commom fungus structure I have seen many times, up close seems to be a very tight group of "dots" that made me unsure of my avaliation.

I posted these pictures in a Discord group, and someone guessed it looks like scratch damage, which would be weird since it is in one of its inner elements. But could have been a not so qualified lens CLA?

Please let me know your opinions, should this be refunded, or no?

(http://imgur.com/WfbKqMR)
(http://imgur.com/p2rTri8)

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Ian C said:

It is useful to read articles about fungus written by biologists—not camera users. Camera users include many who are not experts in the life cycle of fungi. From my readings written by biologists, fungal spores are everywhere and remain inert under conditions in which you’d feel comfortable. But under the proper conditions, the spores begin growing into fungi.

The required conditions are high humidity and, depending on the species (estimated at 2.2 to 3.8 million species), darkness.

https://en.wikipedia.org/wiki/Fungus#:~:text=However, little is known of,can be pathogenic to humans.

If you had a lens with fungus stored in a cabinet or other enclosure, so long as interior air remains relatively dry (45 to 55 % relative humidity), fungus cannot grow and the other lenses in the enclosure would be unaffected.

If the lens you have has some fungus, so long as it is kept in a sufficiently dry environment, it will not support further fungal growth. What you see (if it is fungus) is old, dead residue, not active growth.

Here are some useful ideas from Zeiss:

https://www.zeiss.com/consumer-products/us/service/content/fungus-on-lenses.html

Note: UV light can kill and therefore prevent fungal growth. It cannot eliminate the dead residue of fungus that has already formed on lens or other surfaces. It cannot repair damage to coatings or glass once it has occurred.

There are many modest-priced digital humidity gages available that can be kept in your storage container to monitor the humidity. The battery usually lasts for 1.5 – 2 years in my experience.

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loccdor said:

is anyone else experiencing this?

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Ian C said:

It is useful to read articles about fungus written by biologists—not camera users. Camera users include many who are not experts in the life cycle of fungi. From my readings written by biologists, fungal spores are everywhere and remain inert under conditions in which you’d feel comfortable. But under the proper conditions, the spores begin growing into fungi.

The required conditions are high humidity and, depending on the species (estimated at 2.2 to 3.8 million species), darkness.

https://en.wikipedia.org/wiki/Fungus#:~:text=However, little is known of,can be pathogenic to humans.

If you had a lens with fungus stored in a cabinet or other enclosure, so long as interior air remains relatively dry (45 to 55 % relative humidity), fungus cannot grow and the other lenses in the enclosure would be unaffected.

If the lens you have has some fungus, so long as it is kept in a sufficiently dry environment, it will not support further fungal growth. What you see (if it is fungus) is old, dead residue, not active growth.

Here are some useful ideas from Zeiss:

https://www.zeiss.com/consumer-products/us/service/content/fungus-on-lenses.html

Note: UV light can kill and therefore prevent fungal growth. It cannot eliminate the dead residue of fungus that has already formed on lens or other surfaces. It cannot repair damage to coatings or glass once it has occurred.

There are many modest-priced digital humidity gages available that can be kept in your storage container to monitor the humidity. The battery usually lasts for 1.5 – 2 years in my experience.

Click to expand...