One of the reasons I enjoy using old Minolta lenses is the feel of them, especially the smooth damped focussing action. One of my favorite lenses began to feel a bit gritty and rough when I focused it, so I decided to try and take it apart. Turns out there is a dude on youtube who has excellent instructions on how to do this: https://www.youtube.com/channel/UC89vHLITb7DWKe07_hSWYBw I managed to fix the focusing action on that lens, and it gave me the courage to go back and fix another lens that was focusing past infinity. Adjusting a Rokkor so that it focuses exactly to infinity, with the adapter you are using, is actually really easy. Much easier than cleaning the focusing mechanism. You don’t have to follow all the steps he does in the video to achieve this, but it is worth watching the start and end of the video to see what is involved. Don’t blame me if you ruin a lens! I tried it out first on a lens I wouldn’t miss much.