bleirer wrote:
One spot might not impact the image very much or at all, since the light from one point in the world is entering everywhere on the lens surface, not just that one spot. Take some shots and see. Could be just a little correction in your editor will clean it up.
Do this and avoid ruining the lens. In my experience, and I have many old lenses, only a LARGE OPAQUE spot will impact the image to a noticeable degree. If a drop in contrast (the typical impact) occurs just fix it in PP and have fun with your find.