Beating Lens Fungus

January 29, 2010

Photo Gear

While most folks might find the idea of living and photographing in Hawaii as paradise, for a photographer living at the edge of a rainforest, the battle to protect his cameras and lenses from fungus is a constant threat.

After losing a 300mm 2.8 lens to the stuff, Maui photographer Zane Mathias decided to get proactive to win the battle. He created a camera/lens storage box, powered by a 60-watt incandescent bulb, to keep the fungus at bay.

Mathias started with an old steamer trunk that doubles as a coffee table in his tiny jungle home. He gutted the interior, then drilled some holes in the back – one for an electric cord and the rest to dissipate heat.

The next step was to affix extra lens butt caps onto a board, one per lens, and placed the board at the bottom of the case. Each lens stores vertically, attached to its own butt cap.

“Make sure you test the spacing,” he adds, “and leave room for future purchases.”

The final step is to install a shop light with a regular incandescent bulb.

“Sixty watts will do it,” says Mathias. “Don’t use fluorescent lights. They don’t give off the heat required to stop the fungus.”

Then close the case and turn on the light, which burns 24/7. That’s it.

“Since creating this storage case,” he adds, “I’ve been fungus-free for more than eight years. Living in a place where it rains every day, that says a lot.”


This post was written by:

- who has written 3 posts on The Digital Photo Experience.

Terrie Eliker is a photographer, writer and graphic artist based on the island of Maui. She is also creator and creative director of the Maui Photo Festival & Workshops. or

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16 Responses to “Beating Lens Fungus”

  1. Marjo Aho Says:

    This is such a great idea! I’m in the virgin islands and just had my 70-200 2.8 L USM IS our of commission for a few weeks while it was being “defunged” at Canon. Fungus is an annoying problem for me as I shoot a lot “on the water” (and underwater, but that is generally not a problem). I have one question: If you build an enclosure like this, I would imageine that the 60 wall incandecent bulb wuld make the eclosed space very hot. Wouldn’t this be harmful to the lenses? What would be the ideal temperature? I am now ispired to build somehting like this out of an big old server enclosure – maybe include some fans into it. Thank you for a GREAT idea!


    • zane mathias Says:

      Hi Marjo: You don’t need to add fans. That heat from the 60w bulb creates it’s own fan!(no fluorescents!) That’s the whole idea. I drilled a dozen or so 3/16″ holes in the back of the trunk to dissipate any excess heat. I was going to drill a hole in the side to install the shop light OFF of the floor but after checking the heat levels I leave my light on the floor with no problems. We live on the wet side of Maui & it’s very moist here.. I use most of the lenses in the trunk on a regular basis & I don’t worry about fungus any more! If you open the trunk & thrust your hand in.. It’s not like an oven. you’re going to feel a subtle change in temp.


  2. Soren Hedberg Says:

    So does he leave the shop light laying like that? Is that all the lenses need to prevent fungus? I need to set something like this up, thanks for the great article!


    • zane mathias Says:

      Hi Soren: I NEVER turn off the light. I may have to replace the bulb twice a year. For me the shop light is a safety thing. If you’re concerned about the heat generated by the bulb….you might drill a hole in the side of the trunk to elevate the light off of the floor. Be sure to drill a series (a dozen or so) of small holes (3/16″diameter plus or minus) in the back of trunk near the bulb for heat dissipation. After running it for a while check the heat around the bulb just to assure yourself there’s no problems. Now get out there & find a really cool old trunk & get to work! Aloha, Zane


  3. Angela Says:

    How can you tell that you have fungus?! Yuck!!!!


  4. zane mathias Says:

    Hi Angela: That’s a great question to ask under the “contact us” column. It’s so gradual that it creeps up on you! It looks like a miniature leafless tree growing in your lens. It gets bigger & bigger & it eats the glass! Aloha, Zane


  5. ed Says:

    Do you need to keep the lens caps off to let light in or is it not important?


  6. B W Thomas Says:

    Interesting approach Zane. It is a subject I am pondering after spending a lot on new glass and photographing in damp conditions and where there can be fungus about (in a greenhouse). I read all the Canon literature which suggests if moving from areas of different heat (thus air density = air flow into / out of the lens body = spores & condensation = fungus) to bag the gear in a sealed plastic bag untill the gear has reached the temperature of the current environment. Did you ever try just bagging up your lenses in this way?

    I am about to try shutting lenses in container containing silica gel capsules. The flaw I could see with your set up is the warm lenses, when removed from the case, will cool and suck in air that maybe dirty which will over time build up. Using silica gel there is little heating of the lenses and thus less sucking up of dirty air. On the downside with the gel is that there maybe a lot of silica ‘dust’ in the cabinet that may get into the glass. OTOH with out a change in temperature the drying effect may not ‘reach’ into the lens.


    • zane mathias Says:

      Hi B.W. Sorry I’m so tardy: My assignments range in elevation from the beach to 10,000ft. No problems with changes in temperature.(the change is gradual probably due to driving times) Don’t mess plastic bags,silica or anything. I have a lot of lenses in the trunk and (knock on koa) closing in on a decade, I’m not going to overthink this. That little 60watt bulb is doing it’s job.


  7. Adam Says:

    Why do you leave the lens caps off?


    • zane mathias Says:

      Adam: Sorry I’m so late in responding…Not an expert here but since fungus thrives in a dark moist environment I leave the caps off so the glass is bathed in light.


  8. Jay Says:

    Aloha Zane,
    Great idea! Question: Do you think a small heated dehumidifier bar will do the same thing? I have one that is about 18″ long and uses about 20 watts. It gets warm (almost too hot to the touch) and is made for dehumidifying enclosed closet spaces. I was concerned about the posibility of fire, not having to replace the bulb, and the lower energy usage, which as you know is very expensive in Hawaii (I live on Oahu). Mahalo!


    • zane mathias Says:

      Good grief Jay, It’s only taken 4 months to answer you! I don’t want to send you down the wrong track here. I would think the heater bar should do the trick. I’m SURE the 60watt bulb does. Lets hope some one out there gives us some input. I’ll never be this tardy again Jay.


  9. drew Says:

    Love the article, and have constructed a lens box ( though smaller), similar to your advise.

    What I have found is that the lens bodies get quite warm ( Using a 40w bulb, ) Have you had a problem with melting grease etc.

    Excellent article..thanks for posting it


  10. Zane mathias Says:

    How about this for a rapid reply! sorry so tardy Drew. the approximate dimensions on my trunk are:4’x2’x 1.5′ lots of room for air movement. You may need a larger enclosure….my 60watt bulb is definately NOT melting grease. Z


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