Modern lenses cannot get fungus ..??

[Pistnbroke]

I purchased a Tokina 400mm f5.6 for a very cheap $50 inc post . Quoted as having fungus. On arrival the fungus was  deep in the lens so I just used it and it was fine at in camera contrast +3.
Investigating fungus inspired by the Leica UV lamp/cap I discovered that old lenses used organic cements and coatings  which are food for fungus while modern lenses  do not have this organic content...

so my lenses live in a floor safe ,insulated and heated to about 23 deg C..possibly less in winter ,dry with silica gel ...
do you think this is a good environment ? Too hot ?   and is there any way to halt the fungus in my Tokina?

[Bjørn Rørslett]

Probably anything with glass inside can get fungus, if the conditions for fungal growth are conducive enough. Thus, low moisture levels and lots of sun light should help.

For your Tokina, set it up to point to the sun as often as you can. Do make it out of focus (set to near limit) so as to avoid burn damage behind the lens .... If rainy weather is imminent do move lens in side or it'll get filled with precipitation (been there )

[the solitaire]

There are a few things these fungi feed off. Food contaminants carried by the air when cooking, Skin cells shed that fell to the floor and are picked up by wind when walking by, microbes carried by the air that normally live there etc. Modern lenses are just as susceptible to these as older lenses. Maybe even more. When zooming in and out lenses move air. This air contains many different contaminants,a dn if moisture is higher these contaminants set on the glass surface. The fungi like this because the glass surface, for them, works like a spiders web in gathering nourishment. When it's dark (inside camera bags or closed cases), a bit moist and over 20 degrees, they start growing. At higher temperatures and moisture levels they grow faster.

IMO the best way to store lenses is out in the open, where UV light can make the habitat uneasy for fungi.
In a (non-UV protected) glass cabinet you could store older lenses very nicely. Alternatively, in a cool room in pelican cases with silica gel is a proven method)

Fungi need:
-Nourishment
-Darkness
-Moisture
-Temperature

[PedroS]

Indeed fungus can (and they will) go everywhere.
If you happen to have closed spaces with silica, please measure frequently the humidity and regenerate that silica often. If not it's just there for nothing.
Also don't think that a small bag of silica is enough. To give you an idea, to keep my safe, 1,5 cubic meter, around 40% humidity I need 2Kg of it.