Some say that fungus spores are everywhere and will grow in lenses that are not properly stored - dark, damp, and with poor ventilation:
Originally posted by boriscleto
A lens with fungus will
not "infect" another lens. Fungus will grow in any lens given the right conditions (darkness & moisture).
This lens alone is not really worth investing in the tools needed to open it, but if you plan on buying more old lenses if the future it might be worth it. You will need something to open the lens from the front and a JIS screwdriver set.
Lens Ring Tool Set Screwdriver, JIS Type S Set, 5Pc Steel
This
page recommends a fungus treatment of 94% distilled water, 4% clear ammonia, and 2% hydrogen peroxide. Personally I just use diluted hydrogen peroxide I purchase at the drug store.
Others say that fungi will spread across photographic equipment and that repair shops often do not accept such equipment for repairs because of this risk (even Carl Zeiss does not - see
Carl Zeiss camera lenses service info: fungus on lenses).
Originally posted by Wheatfield
Here's my take on fungus:
Get rid of any equipment that is infected unless it is worth having the equipment completely stripped and cleaned.
Consider, if fungus on one lens won't infect a different one, how did your lens acquire it in the first place?
Spores can drop out of your lens into your camera during use and be transferred to another lens fairly easily.
That lens is a dime a dozen cheap, trash it, forget it and move on.
I would like to have an expert opinion about this - preferably from the likes of Adam, Ole, creampuff, or falconeye (Falk Lumo) - as there does not appear to be any consensus on this topic.
--DragonLord