Recently I took my old Minolta film camera out for its annual airing, after shooting 24 exposures I wiped it down and rewound the film, and removed it. For the shoot I put on the 70-200 Vivitar zoom lens, by chance I looked through the lens and could see what looked like a grease smear on an internal lens this covered about 20%of the glass from the side out. My immediate thought was Fungus, have just got my film back from developers, and all exposures are fine. Now I am wondering how much of the glass do we actualy use after light has passed through the front glass, and will the growth spread,12 months till I find out. Lens is 38 yrs old now.