One of my DSLRs is affected by fungus, and I have a query that keeps on revolving around my mind. If i keep any lens attached to this DSLR and use it, will the lens also be affected with the fungus?
Attaching a lens to a camera body with evidence of fungus in it will certainly increase the chance that fungus spores will make their way into the lens, especially if the lens is one that changes volume with focusing or zoom movements. Such movements pump air in and out of the lens.
Whether the spores are able to flourish and give rise to a fungal colony in the lens is largely a question of whether the conditions in the lens are favorable or unfavorable to the growth of fungus. The presence of two things and the absence of a third are needed for fungi to grow:
- Moisture. Fungi need moisture to survive and reproduce. They don't need much. The moisture in humid air is usually enough.
- Organic substances. The source of organic substances that fungi need for fuel could be organic resin once used to bond lens elements. Most types of dust also contain organic compounds, though. The primary source of household dust is skin dander, and skin is composed of organic compounds.
- UV light. UV light kills fungus. Exposing the glass elements of a lens to just a few hours of sunlight per month will help to prevent the growth of fungus in a lens. It will not, however, remove the visible remains of the dead fungal colony or repair any glass that has been etched by secretions from the fungi.
More precisely, UV light causes fungus to go dormant. Even months or years later it can start to spread again if the conditions are again favorable.
As with most types of camera gear, keeping your camera in a dry, dust free location will go a long way to preventing the spread of fungus. Periodic exposure to UV rays, either from natural sunlight or an artificial source, will also help to keep in from developing into a problem.
As you know, the camera lens consists of multiple lens elements. Some are air-spaces apart. Some are glued together. The characteristic of the glue is critical. It must be transparent and it must have the proper density (index of refraction). For years, the optical industry used a resin made from the Canadian Balsam pine. Being organic, it is also feedstuff for mold, mildew and other microorganisms. Add moisture and an opportunity for spores to settle, a bloom can occur. In modern times, artificial resins replaced the Canadian Balsam. I say it’s unlikely that the affected lens will transmit this infection. Also, both the Canadian Balsam, and modern synthetic resin, is subject to separation and crazing. This is more likely than mold or mildew. It comes from the resin losing its plasticizer and becoming brittle. This is likely due to improper storage, say in a hot car. Once the resin becomes brittle, vibration does this nasty deed.