I don't think I've ever seen fungus on lens or other camera gear other than a few pictures on the 'net here and there. I keep most all my equipment in a safe with a large rechargeable dessicant container that hangs inside. In that same room I have a large dehumidifier set for 45% humidity. I have to take the rechargeable container out about every 4-5 days when the pellets turn pink and recharge to blue. To date I haven't had any problems.

