Folks - I bought this at an antique/junk shop. Lens is in terrible shape (fungus and haze) plus some of the black paint under the first front element has started to flake off onto the glass. (see image). The iris works like a charm and stops from f9 to f260. Is this lens pretty much useless or is this a good find? Paid very little for it so I figured I would rescue it. It was in a junk shop that had no heat/ac and has probably sat like that for years in the humid and frigid Midwest seasons. I am not able to find much info re this Rodenstock chemco Apo-Ronar lens anywhere. Is this some sort of copy production lens? What is Chemco? I believe the focal length (480mm), allows for 1:1 reproductions from what little I could find re this? Feel free to enlighten me what I have. I am really a 35mm/MF kinda photog, but I always tell friends who junk if something has lots of glass, is heavy, made in Germany and cheep get it and figure out later if it was a good buy later so I had to pick this up instead of let her sit through more painful days with no love. Best!