A Fungus Among Us – Moving Pictures

With what seems like the wettest summer in decades, my garden is giving me a beautiful harvest of tomatoes, peppers and, cucumbers, almost every day. But because of that very wetness, I am losing as much as I am keeping because of rot. There is some kind of white fungus that appears on the lowest fruit on the vines, I guess because it’s so close to the moist soil.

It turns out that this isn’t the first time this month I’ve been visited by fungus.

Here is a close view of the front element of one of the most fungus contaminated lenses. It's not hard to see on this one, since it is on the front surface of the second element, which is rather large. — Here is a close view of the front element of one of the most fungus contaminated lenses. It’s not hard to see on this one, since it is on the front surface of the second element, which is rather large.

A very thoughtful friend gave me a camera bag and a cardboard box full of camera gear, including two film cameras, five lenses, and a dozen or more filters. Wow, that’s so fun, and I’m so grateful when my readers and neighbors think of me like that.

As I began to look over this gear, I discovered that all the lenses had a common malady of many older lenses: fungus growth inside the optical elements of the lenses.

Fungus growth inside lenses happens when lenses are stored with neglect. I expect that these lenses were stored in an attic, garage, or shed where rainwater or wet soil is present.

The problem with lens fungus isn’t that it’s present on the surface of a lens element, but that it is usually present on lens elements that you can’t easily reach.

Here's another look at some of the worst fungus damage. — Here’s another look at some of the worst fungus damage.

Also, while fungus isn’t “contagious,” if it is alive inside your lens, it will continue to grow. To kill the fungus, just leave your lens in open sunlight for an hour or two, preferably not when it’s too hot outside. The ultraviolet part of the sunlight spectrum (which is also the part that gives you a sunburn) will kill the fungus. It won’t, however, remove the damage.

If you see a teeny amount of fungus damage at the edge of a lens, and you have decided you can’t get to it to clean it, don’t worry too much. If there is a lot of fungus damage, it might be reparable, but weigh the actual value of a lens against the cost of repairing it, which involves a professional repair place, and it won’t be cheap. It’s one thing to repair a $3000 lens, but entirely another to repair a $300 lens.

Flare, sometimes called veiling glare, is common in photos made with lenses that have fungus on their elements, like this image made of a timer with a contaminated Nikkor AF 50mm f/1.8. In a world where many of us yearn for better sharpness, fungus in this lens simply ruins the lens. And if you want to create this effect, just put some gunk on a UV filter.