Quote Originally Posted by Katie View Post
Fungus can spread to other lenses?
Yea it sure can.
But the correct environment needs to be present in the first place for the spores to thrive.
Damp dark humid places like some camera bags can even be bad news.

IDK but I researched this once and read on a webpage (take it for what it's worth) that the spores are present all around us anyway. They just need the right environment before they can grow.

Also I wouldn't use toothpaste an any Zeiss glass I own
What about the spores inside the rest of the lens?