To be honest I'd get rid of anything with fungus. I wouldn't want it around my other gear. And no you can't get rid of it with UV. UV can get rid of some spores but not live fungus. Most optical services and optics companies (like Zeiss) won't even accept a fungus-infected lens. To kill it all requires a strong x-ray bombardment. Even then, the glass and coatings are likely already etched and can't be fixed.
Hmm... that's scary. So we should never buy lenses from any relatively large dealers which, most certainly, have had fungus-infested lenses come through their inventory? That pretty much eliminates all the good dealers. Not trying to be an ass, though I do often appear as such. You may very well be right. I don't know but I'd sure like to know.
Originally Posted by Michael R 1974
If your city is of some size there might be a business there that specializes in x-raying welds or forgings for flaws. They probably have more than enough power at hand to nuke anything inside that lens. Might even do it on the cheap for the novelty of it. Screw up your courage and call KEH. Lay it out politely and see what they say, you might be surprised. If it heads south get on the phone and call some commercial X-ray companies. And good luck.
I photograph things to see what things look like photographed.
- Garry Winogrand
Point taken ONF ... I guess my view has always been (paranoid though it may be) I can't control everything, but I'll try to control what I can. You are quite right who knows what monsters have infected the warehouses we get our stuff from, but I'll sure as hell try to keep lens fungus out of my house.
Originally Posted by Old-N-Feeble
Michael... Oh, don't get me wrong. I'm, very paranoid... plus skeptical and cynical.
I, as you do, just want to know the truth.
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Agree with you there. Anyhow for what it's worth, here's the info I posted in another recent thread regarding cleaning lens fungus.
Service Info: Fungus On Lenses
"Fungus means an Infestation of optical instruments with fungus spores which germinate and produce more spores.
Lens surfaces are irreparably damaged by metabolic products of the fungus (e.g. acids). Its damage ranges from cloudiness to opacity caused by the film. The Carl Zeiss T* coating has no significant influence on fungus growth or generation of spores.
Where does fungus come from?
Fungus spores are everywhere and germinate under suitable environmental conditions:
• Growing conditions
• Relative humidity of at least 70% (more than 3 days)
• No or little airflow
• Nutrients (textile lint, traces of grease, varnish, dust and dirt)
• Temperatures between 10 and 35°C
How can fungus be avoided?
Reduce the relative humidity to less than 60% (never under 30% as it is dangerous for the instrument) by storing:
• in climate-control cabinets in which hygrometers maintain environmental conditions
• next to driers (e.g. silicagel orange packs) in the containers
• in a special cabinet whose interior is heated to 40°C (max. 50°C) using a fan heater/ incandescent lamps, thereby reducing the relative humidity
• in hermetically sealed cabinets with fungicides with high vapor pressure (fungicide depot must be replaced at regular intervals)
• in an dehydrator above driers
After the work is done, Immediately clean the instruments. If possible, you can use a fan to facilitate evaporation of surface moisture. Do not use containers made of leather, textiles or wood for storage. Short solar radiation or irradiation with UV light may also help avoiding fungus.
How can fungus be removed?
Note: In general, Carl Zeiss does not accept instruments infested by fungus.
Clean affected surfaces with a cotton wiper that has been soaked with a disinfectant. You can build your cotton wiper, using cotton wrapped around a toothpickin such a way that a ball with a peak forms on the pointy end of the stick. Use pure cotton, no prepared or impregnated cotton. Strongly rub slightly corroded optical surfaces with an optical cleaning cloth, cigarette ash can be used as a polishing aid. Heavily corroded optical surfaces must be replaced. Fungus infestation in the interior of an instrument can only be eliminated through disassembly of the instrument."
"It is nearly impossible to repair lenses that have been damaged by fungus. Fungus usually damages the lens element making repairs impossible because the glass surface has been etched by the acid emitted by the fungus. Even if the lens is completely disassembled and cleaned, and new lens elements are installed, we cannot guarantee that the fungus will not return.
TO AVOID FUNGUS DAMAGE:
Do not store your lenses in any environment with humidity over 65%, or temperatures over 86º F (30º C). In humid environments, a non climate controlled garage or the cargo box of a truck is a dangerous place to store lenses overnight.
If you must use your lenses in an envirorment that exceed the limits stated above for temperature and humidity, you must allow the lenses to dry out. This can be accomplished by leaving the lenses out in an air conditioned room overnight. Do not leave the lenses in their case.
If you believe you are working in a situation that has a high risk of fungus damage to your lenses, you should expose the lenses to direct sunlight. The UV-C content of direct sunlight will destroy the mold spores (but not the living mold colonies). However, the UV-C light will likely not penetrate into the lens, since most glass is opaque to high frequency Ultraviolet light.
Place the lenses on a flat surface with front lens cap off and the front element exposed, and iris wide open. Later you can reverse the lenses so they sit on their front elements and expose them to sunlight through the rear element. Do not do this inside a car or another enclosed space where the temperature may exceed 120º F. This can damage the lubricants and adhesives used in the lens construction and require a complete overhaul.
In a worst case scenario, exposure to a strong emission of X-rays can kill fungus. This can be accomplished by exposing the lenses to the output of an X-ray device, set to a high exposure. This can only be done by trained professionals and you must not be anywhere near the lenses during exposure and all personnel present must be protected behind radiation shielding. Once the exposure is performed the lenses will not retain any residual radioactivity from the X-rays, but the exposure should kill any live fungus or spores."
I guess I've done a fairly decent job of keeping my stuff stored in low-humidity environments. I monitor (via feel and local forecasts) humidity and keep my air conditioners cool enough to prevent excess moisture... often mixing heating/cooling to kill humidity.
I've never seen any fungus in the 30+ years I've owned lenses. To be fair though I lived in north Texas a great deal of my life... very dry if equipment is kept inside. But I moved to south Texas about 15 years ago... and I've adjusted my methods somewhat... adding heaters to A/C to kill moisture. This has cost me in electricity but never in loss of equipment.
Hell... I like the same environment as my photo gear does so no big expense anyway.
Last edited by Old-N-Feeble; 05-16-2012 at 08:24 PM. Click to view previous post history.
Except it's not true. Fungal spores are everywhere and unavoidable, all they need is a place to grow, some warmth and some moisture. Sure you can put this lens in a baggie or incinerate it or whatever makes you feel better, but it won't make your other lenses any safer.
Originally Posted by Poisson Du Jour
If the fungus is accessible, you can clean/kill it yourself easily using ammonia mixed with something (google it), followed by a bit of strong UV (sunshine). It won't come back, though your glass might be etched and cause you some flare.
And nth-ing the comments that "UG" grade specifically includes the possibility of fungus; you should absolutely have known before purchasing that UG means "for parts or repair". I generally buy BGN from KEH as it's specified as being functionally good even if it looks worn. KEH will probably take it back if you pay return postage because they are, after all, really nice people. If you don't want a fungusy lens, get an RMA and some store credit for a better lens.
polyglot... YES... but we can slow the spread of spores to the point that it DOESN'T EFFECT our lenses noticeably.
Keep temperature and humidity LOW!!
That is not fungus, that is separation caused by the failing of the optical cement Schneider used at the time. I have a lens with a snowflake similar to yours that is deeper in the lens. It does not show up in the images. I am not saying yours won't show up, but mine doesn't.
I think you should return it for something else. I bought a BGN Fujinon 210 a little over a year ago at KEH for just over $100 and it is perfect. Your lens probably wasn't much less than that.