About a month ago I bought an F* 300 f4.5 from eBay. It proved to be badly damaged. I sent it back and got my money refunded.
Today I received my second F* 300 f4.5 from an eBay auction. It is a gorgeous lens. Cosmetically and mechanically it is close to pristine. KEH would grade it no lower than LN-, and perhaps even LN. Then I looked through the lens toward a strong light and saw that at least one element is coated with a haze or residue of some kind. It shows up as very small bumps or ridges. The previous owner took very good care of it. Perhaps too good. He apparently stored it around mothcake. The smell is strong. This is not a good idea for lenses, cameras, or electronics. Mothcake gives off a gas and can leave residues. I don't know if that is what I am looking at, but it is some kind of stuff on one or more elements. I haven't tested it yet for optical performance. I had to come in to work today. I called Pentax USA's repair shop to ask if lens elements can be cleaned without damaging the SMC coatings. The guy I talked to said yes. But I thought I should ask all of you: Can gunk (for lack of a better term) be cleaned off lens elements without harming the coatings? I haven't decided yet whether to send it back or have it repaired. It is in such beautiful condition otherwise that I am considering just paying for the cleaning. I am batting 1 for 4 on eBay. I have bought 4 lenses there. Here's the results: Tokina AT-X AF 400. A keeper. Still have it. SMC F 70-210. Frozen aperture. It went back, and I got a good one from KEH (for more). Previous F* 300. Broken, probably had been dropped. Returned. Current F* 300. Outcome uncertain. Many (most?) people don't take very good care of their equipment. I have noticed the same buying used cars. I would be happy to buy these things new if they were available. Thanks everyone, Joe
