Fungus spores are present in an amazing variety, and quantity, in the air all the time. To thrive they require only the proper conditions. For most fungi this is a cool, dark, damp, stagnant environment. And of course, food. Their mortal enemies are light, heat, dryness and fresh air. The coating on camera lenses is organic, here's the food. Take a lens, use it on a nice hot, humid summer day, then store it away in the celler in its leather case, soon you'll have a nice fungus crop started. And, *even then*, you probably will never see any fungus on the outside of the front and rear elements because the air isn't stagnant *enough*. The leather case itself, though very good at drawing and holding moisture from the cellar, 'breathes' enough to keep the air around the lens relatively fresh. Only the inside of the lens, which breathes, but very little, has a stagnant enough environment for fungal growth. To prevent, or arrest, fungal growth store the lenses in a dry place with plenty of fresh air. Silica Gel packets help, a cabinet with a few small holes in the top and bottom and a small light bulb in the bottom to act as a "damp chaser", helps even more. This is a perfect setup for 'collectors'.
Even better yet, take all your lenses for a "walk in the sunshine" frequently. It's good for them and you might get some nice photos too! ;-) BTW: Fungi do not "eat glass", it is the acid they excrete as a by-product of digestion that 'etches' the glass. End of Biology 101. ;-) Don > -----Original Message----- > From: David Oswald [mailto:[EMAIL PROTECTED] > Sent: Tuesday, May 03, 2005 12:15 AM > To: [email protected] > Subject: Re: old lenses > > > It does sound like the spider-web looking marks are probably fungus. > Whether or not this can be cleaned depends on how bad it is. At worst, > it can actually etch the optics in an irreversable way. If that's > happened, some of the optics would have to be replaced, and if the lens > is long out of production, you're not going to find replacement glass. > > However, if the fungus hasn't had time to do its evil work on the glass, > it may be cleanable. > > I don't know exactly how lens fungus spreads, but I'm very paranoid > about it, and the one time I bought a lens on eBay that appeared to have > fungus, I immediately quaranteened it, keeping it far away from my other > camera equipment. Eventually I was able to work it out with the seller, > and I sent it back to him. I didn't even want to mount it on my camera. > Fungus spreads with spores, right? That being the case, it can spread > to other lenses stored nearby (that's 100% pure theory; I'm not sure at > all). > > > > Ian Lind wrote: > > I came across several old Pentax lenses which have probably been in > > storage for at least 20 years. > > Nothing fancy. There's an 85 mm, a 35 mm, and a standard 50 mm. > > > > They aren't beat up, but when I hold them up and look through them, > > there appears to be fine bits of dust on inside surfaces, and > other very > > fine "stuff" that almost looks like mini-spider webs. > > > > Is there any way to do interior cleaning of such lenses or > should I just > > dump them? > > > > If it's pretty hopeless, I'll offer them to someone who might want to > > experiment... > > >
