[fs999]

Is it possible to submerge a whole lens in a 99% isopropanol bath to completely remove fungus ?

[Stone G.]

I wouldn't try to do that: You might kill the fungus, but the remains will still be there, and very visibly so.

Further, alcohols will dissolve all lubricants and most likely damage non-metallic sealings etc.

[fs999]

That's what I thought. Thank you !

[topace]

Image quality isn't just about the glass either. coatings are also very important, and while the outer coatings on the outer elements have some resistance to hostile environments, inner coatings are actually rather sensitive.

Even the most simple of modern camera lenses is the culmination of hundreds of years of research into mechanics, optics and most recently, electronics. I'd recommend treating it as such. For fungus problems, I'm afraid disassembly and careful cleaning is the only way to go.

[miltona580]

Probably the best thing to do would be to seal it in a watertight case with some silica gel. You will still need to clean the elements, but it should starve the fungus of its needed moisture.

[kh1234567890]

In my experience with cleaning old lenses fungus usually starts growing on a bit of organic matter that had got in, usually some nano-insect that had got in and could not find a way out