Originally posted by monochrome
Was it the actual coating, which had been chenically changed by the fungus, then you wiped it off?
Thats what I thought when I first saw it on the vivitar filters. On them, most of the coating had been eaten away. On this latest lens though (the pentax A 50mm 2.0), after cleaning it off, the coating seemed to be fully intact. It still had that colored dim reflection that you get with a coated lens on the surface that it was cleaned off of. The coating seemed to be unblemished at all.