The lens is 60 years old. It's my father's lens. We haven't been using it much. The focus ring has become too stiff, I can hardly move it. it is harder when I try to focus towards infinity. Not impossible but I get the feeling I might force it too hard and break something. will it get better through using it more and more or should I just have it fixed. In the crisis we' re living it is too expensive to spenf 60 euro, if I can make it better just by using the ring more often. Extremely nice lens by the way.