I have a Nikon 50mm 1.4 manal focus AIS lens in almost new condition except for a bit of wobble when I focus. It seems like the focusing ring is not as tight as it should be. When I turn the focus ring and aquire a perfect focus, I notice a bit of wobble that shifts the front focusing ring/element and takes the image out of focus. I have other lenses that have similar issues to a smaller degree. I was wondering if there is an easy repair for this. Replacing these lenses is not a smart idea at this time because the glass elements are near perfect. The lenses are almost new except for that little wobble issue.