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Message: <blockquote data-quote="Hermann" data-source="post: 2727533" data-attributes="member: 4925">Good question. I've never seen anything like it, and I've seen some badly damaged coatings over the years.The best way to check is to use a magnifiying glas with a fairly high magnification (I prefer 6x or 8x). Move it towards the eyepiece lens until some speck of dust on the lens is sharp and check the funny spots. If there isn't any clearly visible damage to the lens or the coating, continue moving closer, thus focusing on the rear of the eyepiece lens. You should then be able to determine is there's anything on the rear of the eyepiece lens. Fungus in particular is pretty easy to identify this way. But that doesn't look like fungus to me at all.Hermann</blockquote>