[NiftyFifty]

Is there any way to kill fungus on a lens? I bought a Pentax-A 50mm f2.0 lens from KEH via eBay for $22. The listing DID say there was a small fungus spot on the front element of the lens, but that they didn't think it should affect any pics. I figured for $22 I could afford to take the chance.

But, I just read in another thread that fungus can spread from lens to lens and now I'm nervous. I haven't put this lens with my other ones yet, and now I'm glad. I'm wondering if I should return the lens to KEH and just tell them to give me a store credit, because I do buy from them a few times a year. What do you guys think, and is there a way to kill that little fungus spot (and it is little) on the front element?

I'm thinking something about UV exposure? *confused*

[jatrax]

But, I just read in another thread that fungus can spread from lens to lens and now I'm nervous.

Total BS.

The fungus in your lens is already DEAD. You cannot kill it any deader. If it was not dead then it would still be growing and covering more of the lens, which it is not. Fungus requires moisture and food to grow, it usually starts when the lens gets water in it, either directly or by condensation. And when the moisture dries up it dies. End of story. Fungal spores are in the air we breathe all day. They are already in all of your other lenses, in your camera and on everything you touch. The only way to keep them from growing in your gear is to keep it dry and if it gets wet to dry it thoroughly and completely.

The only way fungus can spread is through spores which are formed on fruiting bodies. A mushroom is a fruiting body. I have never seen fungus live long enough in a lens to actually grow a fruiting body. Not saying it could not happen but if it did the entire lens element would be white not a little speck.

What you see on the lens is a bit of dried up mycelium and it shows the extent that the fungus grew before it died. If you want to clean it then you need to open the lens and clean with alcohol or other cleaner. Bu this just removes the detritus, it will not prevent fungus from growing again if the lens gets wet because the spores will be present.

Fungus can permanently damage a lens because some species extrude an acid that can etch the class or ruin the coating but this happens only in extreme cases.

Every time I see this myth repeated I have a vision of white fungal threads growing out of a lens across the camera bag and into another lens. Still waiting but I've never seen it.

[NiftyFifty]

Total BS.

The fungus in your lens is already DEAD. You cannot kill it any deader. If it was not dead then it would still be growing and covering more of the lens, which it is not. Fungus requires moisture and food to grow, it usually starts when the lens gets water in it, either directly or by condensation. And when the moisture dries up it dies. End of story. Fungal spores are in the air we breathe all day. They are already in all of your other lenses, in your camera and on everything you touch. The only way to keep them from growing in your gear is to keep it dry and if it gets wet to dry it thoroughly and completely.

The only way fungus can spread is through spores which are formed on fruiting bodies. A mushroom is a fruiting body. I have never seen fungus live long enough in a lens to actually grow a fruiting body. Not saying it could not happen but if it did the entire lens element would be white not a little speck.

What you see on the lens is a bit of dried up mycelium and it shows the extent that the fungus grew before it died. If you want to clean it then you need to open the lens and clean with alcohol or other cleaner. Bu this just removes the detritus, it will not prevent fungus from growing again if the lens gets wet because the spores will be present.

Fungus can permanently damage a lens because some species extrude an acid that can etch the class or ruin the coating but this happens only in extreme cases.

Every time I see this myth repeated I have a vision of white fungal threads growing out of a lens across the camera bag and into another lens. Still waiting but I've never seen it.

Thank you for the explanation and the chuckles I got while reading it - "You cannot kill it any deader". For some reason that just tickled me. Good to know that I'm okay keeping the lens and doing nothing. Oh, and no... I won't be doing "lens surgery" to get the little speck off. After reading your educational post, I figure that KEH already did everything to it that could be done, and they're not known for selling unusable stuff without warning. I've bought "bargain" lenses from them that looked brand new and have NEVER had a problem with anything I've bought from them, so I'm very confident in them. Their 6 month warranty on used items helps as well, LOL.