Once bitten, twice shy, or so they say. Whoever 'they' are, they're wrong :lmao: because I'm still buying lenses of eBay, and they're still faulty . This time I picked up a 35mm m42 lens which was not in great cosmetic condition but appeared to have clean glass. When it arrived I checked it over and it did seem to be pretty good optically. But when I held it up to a light I spotted a small patch of what looks like oil on an inner element. I'm assuming it's oil because although it's completely clear, if it was water I suspect it would have dried up. Anyway I was wondering if anyone has had a similar problem or knows how this would affect the lens' optical quality. It's only affecting a relatively small area on one side of the element, but I'm assuming the effect will still be noticeable. Also, can anyone suggest a way of cleaning it? My first thought is to seal it in a box with some packets of silicon gel, but I don't think that works with oil. Also I can't disassemble the lens because, as seems to be the case with every lens I have a problem with, the four screws at the back of the lens will not budge. I think not noticing or mentioning this was an innocent mistake on the part of the seller, so I'm not going to hunt him down and wreak terrible vengeance (also the lens cost me £0.99 :mrgreen but obviously I'm still looking to make it work if possible. Any advice at all would be great. Thanks in advance!