Lens fungus

[photobackpacker]

I shoot mainly in the upper midwest where your equipment will actually frost over when you come in from a long outdoor winter shoot. To avoid this, I put my entire LF backpack in a plastic bag and allow it to warm up before unpacking it.

Among the many problems this condensation could cause, I worry about lens fungus. To be truthful, I don't know anything about lens fungus, except that I don't want it!

• What conditions cause it to form?
• Where on the lens does it usually form?
• What does it look like?
• What is the best way to prevent it?
• Are there any authoratative articles or literature on the subject?

Thanks

 

[Brook]

Im sure others can give a more complete answer, but up here in the tundra, I dont think we have a lot to worry about if you keep them in a dry enviornment, like not keeping them in a sealed damp case or basement. I have only seen fungus on pretty vintage stuff or wet basement victims. If you see moisture between the elements, leave it in a warm, not hot, dry place.

 

[John Koehrer]

Blaughn,
Usually forms on inner elements.
Warm, humid storage will encourage formation.
Almost looks like a root system from a tree, although (obviously) on a much smaller scale. Usually appear silverish in color.
Prevention is easy, store in a dry space. You can use a silica gel to help absorb moisture. Temperature isn't important since fungus will form just about anywhere here in the states.

 

[Carol Flutot]

Hi,

If your lenses are being subject to continuous condensation, you may have to worry more than just lens fungas, moisture can collect and cause rust on any metal parts too.
Fungus can appear anywhere on the lens surface and will look like a fog or little crystal
webbing, that doesn't go away, after they have been dried out.
Moisture causes the fungas!
If you do notice any fungas on your lens it is best to get to taken care of ASAP before
it starts etching into the coating and the glass!

Carol

 

[JG Motamedi]

In addition to fungus, I had a problem a few years ago in which condensation between lens elements in reaction with the rare-earth elements of glass created, as John Van Stelton decribed it, "a corrosive cloud" which started to etch the glass. Luckily I caught it early before it ruined a wonderful lens.

 

[colrehogan]

I should be getting a lens back today from being repaired (it also had some fungus which had etched the glass).

 

[Bruce Osgood]

This is a question for our member Carol Miller:
flutotscamera@earthlink.net

As far as I know if you've got fungus you keep it. It can be removed but comes back again, maybe a year later.

 

[Carol Flutot]

Hi Bruce,

I have been removing fungus for a long while for folks and once I remove it
they haven't brought them back for further cleaning. Than again, I am out here in Southern California, so fungus isn't a big problem and once it's cleaned it is not really subjected to humidity, ect. that causes the fungus.

So I can't tell you want happens, if it's the same fungus or new fungus that comes
on from further exposure to moisture.

Most of the fungus cases I get are from items that were stored improperly for long periods of time or were purchased with this problem.
So that is my experiance with fungus, I am positive that those repair folks living in mid & east coast would have more knowlege than I in this area.

Carol

 

[Bruce Osgood]

Hi Carol

I hadn't considered there was more than one kind of fungus, makes sense that there would be though. Kind of a regional thing I guess.

 

[roteague]

Kind of a regional thing I guess.

I think you are right, all my lenses now have some form of fungus, which they never had before I moved over here.

 

[Dave Dawson]

I have been told that if a lens has fungus and is placed in a dry sunny place for a few days the fungus dissapears or is that an old wives tale?

I think the theory is that the uv kills the fungus?????

If this is a load of rubbish please be gentle with me!!!!

Cheers Dave

 

[eddym]

If the fungus has already etched the glass (which, by the time you notice it, it usually has), then you can kill and/or remove the fungus, but there is nothing that can be done about the damaged glass.
This is the sad voice of experience speaking.

 

[mrmekon]

UV will kill the fungus spores so it won't continue to grow, but it won't magically clean up what's already there. I've been wondering if a full-spectrum fluorescent bulb gives off the right UV wavelengths to kill it. Would periodic flooding under UV lamps be a good preventative measure?

 

[ic-racer]

This is one of the best monographs on lens fungus that I have read. It has no references though. The writer is Gordon Ian Stalker BSc, who I believe is a camera technician rather than a mycologist.
http://www.mypentax.com/Fungus.html