UV light for keeping out fungus in lenses?

[d._david_young]

Living in Hawaii I have to put my lenses out in the sun as we have humid weather here. My

method doing this is to put my lenses in an opaque airtight plastic bag with some

dessicant or crystals that absorb water and leave it in the sun for a while. I then take it out

of the bag and flash the lenses on both sides in direct sunlight. I was wondering if using a

UV light ONLY may work at keeping fungus at bay as it would entail less steps, work and

worry about getting condensation into the inside of the lens. Has anyone a better method?

How often is often enough?

thanks for answering!

[r_scott_steube]

Try this link for a handfull of ideas/info: http://www.chem.helsinki.fi/~toomas/photo/fungus/. UV light will work at inhibiting fungus only if powerful/consentrated enough. I've often shot in extended damp but cold climates and have had condensation problems but no fungus. So if failing to keep your lenses dry, at least try to keep them cold. Good Luck!

[Gary Naka]

Hi Dave

 

Where do you live?

I never had to do what you are doing.

 

But I used to live in Hilo for a couple years...and you know how wet Hilo is.

 

I put a dehumidifier in my closet and anything that was subject to mildew/fungus was kept in that closet. This included my camera gear and leather shoes. As I recall I pulled out about a half gallon of water every week.

 

When I left Hilo, and had stuff in storage before being shipped to the mainland, guess what...mildew on my leather stuff :-(

 

The non-electrical option is to put the gear into a sealed plastic box like a tupperware with a LARGE desicant pack, not the tiny packets that is in the gear when you buy it. Just watch the mosture indicator on the desicant, and recharge it before it gets saturated.

 

aloha

Gary

[d._david_young]

thanks for the feedback,

R Scott, thanks for the helpful link and ideas.

Gary, I live on the east side of Oahu and we just had a lenghty storm system with alot of

rain. Not as rainy as Hilo, though. I bought a used lens and it has developed some strange

swirl like opaque stuff in the inner elements after a few years so I am afraid the other

lenses may get it also. The sealed tupperware idea with indicator crystals sounds the best

way if one does not want to invest in a humidifier!

[gluteal cleft]

The balancing act with UV is getting enough to inhibit the growth, without being so much that you break down any rubber, plastic, paint, etc..

[wai_leong_lee]

Modern coated lenses filter out UV, right? How can fungus be killed then?

[rdkirk]

I lived in Hawaii for 8 years, as well as another 12 in the Philippines and Okinawa. I never had to do all that.

 

Fungus needs two things to grow: Seventy percent relative humidity AND 24 straight hours of it. If you deprive it of either, it won't grow. UV isn't a particular factor. Fungus is NOT any more particularly vulnerable to UV than is any other living thing. If you give it enough UV to, say, kill off human skin cells, it will kill fungus.

 

It's hard to remove moisture from the air. Trying to keep equipment in sealed containers with a dissicant is a BAD idea. You have to know how much dissicant you really need for the volume, and you'll have to renew the dissicant (heating) every time you open the container. If you're not exceedingly careful, you will most likely succeed only in creating a humidor to grow fungus.

 

First find out for sure how much of a problem (if any) you really have. Go to a home store and buy at least 3 inexpensive hydrometers. They can be as cheap as $3.00. Get at least 3 so you can go by the two that agree. Test them in your primary storage area as well as other areas in your house. You may find that one closet is too humid, but another is fine. You'll also see that various areas of the same room can vary greatly in humidity (the corners near the floor will often be much more humid than the center of the room. Put some in your camera bags and cases, too.

 

Remember that you're interested in finding a place that drops below 70% humidity for at least 8-10 hours a day. That's all you need. You may find that all you have to do is get your equipment the heck out of closed bags and closets. I NEVER store my equipment in bags or cases--I always keep it in non-sealed cabinets or drawers (if you are in an air-conditioned house, get a cheap chest of drawers for your equipment).

 

Relative humidity is a function of both moisture content and air temperature. It's hard to remove moisture, but it's not hard at all to raise the temperature a few degrees in a moderately enclosed cabinet.

 

When I was in Okinawa and the Philippines (with no air conditioning), I comandeered a kitchen cabinet and mounted a 30-watt light bulb in it. I stored my equipment on the shelves covered by a light towel to keep off dust. The cabinet was not air-tight, but the solid wood walls permitted just enough controlled air flow to allow the bulb to drive out humidity. I ran it at night. All you need is a few degrees of warmth for 8-10 hours a day.

 

You also can buy expensive "dry boxes" designed for guns and such--they are just cabinets with small heating elements. But putting a small electric bulb in a cabinet works well.

[q.g._de_bakker]

UV light (sun) and freely circulating air help keep fungus a bay.<br>So put the lenses in the sun, but keep them out of the plastic bags.

[r_scott_steube]

Hello Again and here are some follow-up ideas�

 

Even though I shoot with Canon�s instead of Weatherby�s I figured I check Cabelas.com and found:

http://cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0034792227686a&navCount=7&podId=0034792&parentId=cat20799&navAction=jump&cmCat=search&catalogCode=XF&rid=&parentType=index&indexId=cat20799&hasJS=true

and

http://cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0005569210423a&navCount=7&podId=0005569&parentId=cat20799&navAction=jump&cmCat=search&catalogCode=IG&rid=&parentType=index&indexId=cat20799

 

These items address two opposite techniques, but perhaps effective approaches to inhibit fungus growth: 1) Desiccant in an air-exchange resistant box/case or 2) Heating unit in a free flowing air-exchange box/cabinet. The former is easier on-the-road and no electric power needed (except for re-charging desiccant unit). The latter perhaps more leave-it and forget-it solution at home.

 

I did some asking around with bio-medical and research labs colleagues where cost is no object, e.g. $20,000 Dry Cabinets, and their consensus is that 40%-50% RH range is the goal. Cheap humidity gauges that you can buy at Wal-Mart etc. are notoriously inaccurate, but they will correctly tell you the trend over time in RH. The interior is getting dryer or damper�

 

Staying away from camera bags etc, than retain moisture, i.e. leather or cotton is a big deal.

When I travel to humid climes, sometimes I can have A LOT of gear; so far pelican cases and 10-20 pelican desiccant units have kept me out of trouble. But whenever there is the opportunity to dry out everything out in an air conditioned room, time must be made.

[d._david_young]

thanks for the ideas: got to keep the cameras and lenses out of plastic bags long term. But

they do keep dust out of the camera bodies particurlarly digital ones, for long periods of

time. And they do help to acclimate lenses when moving from exteme hot to cold or vice

versa. Thanks R Scott for the info on the types of controlled environmental units; I don't

have 20 grand to spend on a prime unit but if I did I would buy alot of camera stuff!!! I will

check out those links you posted. I have a glass fronted case, that is not airtight that I

have to test for humidity. I keep all of my camera bodies and gear in there; at least some

sunlight shines on them in the summer months. Thanks for the detailed explanation Kirk; I

will see if I can reach 70 percent humidity for eight to nine hours a day. I guess a sealed

tupperware is a no no unless an expensive lab type super accurate machine.