> > From: "Don Sanderson" <[EMAIL PROTECTED]> > Date: 2005/05/03 Tue AM 11:21:04 GMT > To: <[email protected]> > Subject: RE: old lenses (A bit long) > > 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.
That's the first I've heard of this. Any further information? AFAIK, coatings (such as SMC) are ceramic. > 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... > > > > > > > ----------------------------------------- Email sent from www.ntlworld.com virus-checked using mcAfee(R) Software visit www.ntlworld.com/security for more information
