It really depends on the lens, the position and the size of the fungus. I sometimes buy vintage with haze or fungus, and if I can I clean them up myself.
It doesn’t really reduce the sharpness of the images, but causes a “glow” in bright conditions and around highlights especially at wider apertures; generally the impact is less severe than you would think.
I’d say a lens with mild fungus is worth something like half the price of one without, but this also varies with rarity and other factors.
If you end up getting it, you probably can keep it from growing further by UV sterilizing it (direct sunlight for some time) and then keeping it in a low humidity environment. As others have said, fungus can etch the lens coating, so some impact can remain even if you clean it/have it cleaned, nothing to be done about it.
It really depends on the lens, the position and the size of the fungus. I sometimes buy vintage with haze or fungus, and if I can I clean them up myself.
It doesn’t really reduce the sharpness of the images, but causes a “glow” in bright conditions and around highlights especially at wider apertures; generally the impact is less severe than you would think.
I’d say a lens with mild fungus is worth something like half the price of one without, but this also varies with rarity and other factors.
If you end up getting it, you probably can keep it from growing further by UV sterilizing it (direct sunlight for some time) and then keeping it in a low humidity environment. As others have said, fungus can etch the lens coating, so some impact can remain even if you clean it/have it cleaned, nothing to be done about it.