Yeah, the first thing I did was clean the lens - front and back. I haven't checked the negatives but on some of the prints, I have a couple of little, squiggly dust particals (maybe lint?) and that's also what I'm seeing in the viewfinder. I'll try and see if I clean it better. And yes, I used a lint free PEC pad to clean the mirror and prism. Of course, my husband's had this camera since he was a teenager so I would guess that a cla is in order right about now.