Stop Fungus from Damaging your Lens

Do you have fungus growing inside your lens? Have you ever looked through your camera lens recently? With the aperture wide open, and you see tiny growth which is the mycelium or structure of the fungi.

You see fungi grow in all condition but thrive in areas where there is particularly low water activity where bacterial microorganisms cannot compete. Over time, the fungi excrete secondary metabolites which etched the surface of the lens rendering it useless.

The best remedy is keeping the lens in a cool dry place. Here are some further recommendations to further reduce the risks:

Keep your lenses in a dry, cool place.

If you use your equipment in damp or humid environments, let it dry as soon as you return into a drier room.

Never leave your equipment in a closed (splash proof) camera bag when it need not be there. Leather lens cases are known to be especially bad, because leather is a natural product where fungi can grow before they proceed on to the lens. Synthetic materials are better, however there is no guarantee that it will be free of fungus.

As the majority of lens changes its length when focusing or zooming, outside air is sucked in and out during usage. In humid or moist environment, the insides of the lens may experience an increase in moisture or high water activity which is enough for any potential moulds spore to germinate given the right conditions. To ensure the optimum condition is created, an ideal way is to zoom the lens back and forth several times in a dry room or a room with very low moisture such as an air conditioned room prior to putting the lens or camera away. This is to replace moist air with dry air thereby creating an environment unfavorable for moulds to grow.

If you store your equipment in a sealed airtight case, adding a small bag of silica gel or other water absorbent material may help reduce moisture. You will need to monitor its status which is usually indicated by change color of the silica gel) regularly. As soon as the gel shows signs of saturation with water, it should be replaced or re-activated (heating to remove excess moisture) dried.

The ideal relative humidity to keep their lenses is roughly below 55%. Note, if you go below 30%, the lubricants in the lenses (diaphragm, focus, and zoom mechanisms) might dry out faster than you like. The ideal temperature would probably be around 20 – 25 degrees Celsius or 68 degrees Fahrenheit (Room temperature)