Fungus on optics... Not so much how to clean but what happens after!

[MrFus]

Well, maybe this has been addressed before but all my keyword combinations on Google resulted on the same path... Fungus on lenses is a widely discussed topic, many people asking and many people providing solutions in how safely clean and prevent fungus from growing on the top surface of optic elements, but, BUT... What happens after you cleaned it? How you deal with the damage done to the coatings on the lenses?

If the damage is extensive can the coating be completely removed at the cost of lost of optical performance?

Is really that evident the difference between a lens that has lost the coating due fungus damage compared with a similar lens on better condition?

 

[__Brian]

The damage can etch the glass.

If it is just the coating that is damaged, it looks ugly- but affects only a small percentage. Leave it alone, the intact area of the coating still works to transmit light.

If the glass is etched- you will have a softer focus lens. Use a hood.