What is lens fungus?
Lens fungus is a combination of dust and moisture that finds its way into the interior elements of a camera lens. Dust does not typically cause a problem, but if that dust contains fungus spores and combines with moisture, then fungus can grow. It is more common with lenses that are not weather sealed and used in very humid, tropical areas. It can look like small web-like spots or patches inside the lens. If left untreated, the fungus can permanently decrease the len's performance and cause your images to look fuzzy or hazy.
How to check for fungal growth in the lens
Follow the steps below to check for lens fungus:
- Remove the lens from the camera.
- Be sure to remove the front and rear lens caps.
- Make sure you have plenty of light nearby.
- Look through both ends of the lens to see if you can spot any fungus growth.
If you suspect lens fungus, the lens should be evaluated by a professional lens technician to determine if it can be cleaned.  Go to Product Repair.
Tips to help prevent fungal growth in the lens
While there is no guarantee that lenses will be free from fungal growth, there are some steps that can help reduce the occurrence:
- Monitor the moisture and temperature status in your environment.
- Keep your lenses in cool and dry places.
- Since fungus thrives in dark and moist areas, storing the lenses properly will help prevent fungus growth.
- Store your lenses in a see-through or humidity-controlled cabinet with silica gel packets if you are not going to use them for a long time.
- The silica gel packets absorb moisture, while the see-through container allows light inside that can kill fungus.
- Check the silica gel packets periodically and discard them if there is absorbed water.
- Refer to our Alpha Camera and lens maintenance tips for more details on how to maintain your camera and lens.