What is this business about oily blades ...?
Over the years I must have owned fifty lenses in every format and vintage (since the 1950's, anyway). Never seen oil on a blade. Is this a real thing, an antiquated thing that has carried over into modern parlance, or some weird internet meme that all sellers feel the need to include as a "selling point"?
Anyone here able to show me a photo of a (modern) lens with oily aperture blades?