lens/fungus/mold

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Hi, I had left a lens in my car on a cold winter night maybe for an hour, and when I brought it in the house, the lens elements fogged. It went away, but I was wondering if this is the way lenses get mold of fungus? If so, then what does one do when trekking out on those cold days, then entering into a warm environment.?

-- Raven (mtand13@netreach.net), January 03, 2001

Answers

One answer is to leave your equipment in the car (when not in use) - I do that for weeks at a time in the winter, then you don't have to worry about rapid changes in temperature. Another is to enclose the lens in a "zip-loc" bag - don't worry about squeezing all of the air out, the relative humidity is so low that whatever air is inside the bag is drier than the air inside your house. The trick is to leave your equipment in an insulated container so that it warms up slowly, it's the temperature differential that causes condensation to form on cold objects. A foam-padded camera bag will do. I bought some large collapsable "coolers" that work great. "Fungus" is all around us and probably in almost all lenses of any age. It requires darkness and moisture to grow - eliminate one condition (preferably both) and you'll never have a problem.

-- Wayne DeWitt (wdewitt@snip.net), January 03, 2001.

Hi Raven,

Lens fungus as i undersutand comes form bacteria eating the cement in between the element groups, as the earlier cement was sap from cedar trees, the fungus can be killed by exposure to ultravilot light. Bill

-- Bill Jefferson (jefferw@together.net), January 04, 2001.


Condensation doesn't help, but I don't believe that condensation alone will cause a fungal attack on your lenses.
After bitter experience, it's now my firm belief that the lens fungus migrates from nearby surfaces that have the right conditions to nurture the spores in their early stages. Prime suspect in my book is leather. Leather lens cases, camera cases, lens pouches, get rid of 'em. They may be hard-wearing, and look and feel a lot nicer than PVC coated mand-made composites, but IMHO leather is an ideal breeding ground for fungus, especially if it has a nice velveteen lining to it as well.

I only have circumstantial evidence to back up this rant, but all I can tell you is that since I weeded any leather cases out of my collection the incidence of fungal attack on my lenses has dropped to zero. Before I did this, I had to be constantly vigilent to catch the first signs of those nasty little cobwebs creeping across the edges of my precious glassware.

-- Pete Andrews (p.l.andrews@bham.ac.uk), January 04, 2001.


Bill:

Lens fungus as i undersutand comes form bacteria eating the cement in between the element groups, as the earlier cement was sap from cedar trees, the fungus can be killed by exposure to ultravilot light. Bill

Don't think so. Fungi belong to a different kingdom than bacteria. They are everywhere. To get them to grow, you need some moisture [although members of some species of Aspergillus can grow at desert humidities] and an energy source. That energy source can be quite variable. Some grow on solder flux and cause problems in industrial plumbing. Some grow on jet fuel and cause problem in airplanes. Some grow on roofing material and cause shingles to fall apart. In lenses, it is usually accumulated oil of some kind. Since many produce organic acids as a by-product, they can etch the lens. By the way, many of the offending fungi are quite resistant to UV irradiation. Particularly the genus Aspergillus which is very common.

So it goes. Enough Mycology.

Art

-- Art (AKarr90975@aol.com), January 04, 2001.


Raven,

My lenses have fogged numerous times, usually during the winter when I inadvertantly breath on them, or when moisture from the bellows condenses on the rear cell. They've developed neither fungus, mold, nor mildew, and I don't spray them with Lysol or Tilex. Just put them some place dry for awhile so that the moisture has ample time to evaporate.

Bruce

-- Bruce M. Herman (bherman@gci.net), January 05, 2001.



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