[dkpeterborough]

I've bought several lenses in the past with visible fungus and had them professionally cleaned ... and had one recoated ... and they are fine . A few people on this forum have expressed their concerns about cleaning fungused lenses ... but in my experience if cleaned properly the problem is curable. As for dealers ... well some of them know so little about optics and they can talk absolute rubbish about cameras and photography ... and then again there are very reputable dealers who regularly send lenses for fungus removal and repolishing/recoating if necessary. Fungal spores are present everywhere and will thrive in/on any suitable medium ... especially glass which is subject to condensation. But provided the glass lens is kept in a stable environment and not subjected to extreme sudden changes in temperature it should stay free of visible fungus. Having said that I expect that there are microscopic fungi/spores on thousands of lenses which never develop into a problem because the conditions on the lens are not suitable.

When I was at school we did experiments growing cultures derived from our 'clean hands' ... some of those cultures were fungi ...

So we just cannot stay away from fungus ... fungi are everywhere and waiting for any suitable opportunity. And many are killed by daylight.

Today I've sent the lenses opff to a specialist optical engineer for an estimate ... it is not a matter of can they do the job because I know they can .. more a matter of whether it is cost effective. If not cost effective the lenses will be ditched ... but I hope at least a couple of them will be worth salvaging.

Dunk