so I was recently gifted a Vivitar 120-600mm ƒ/5.6-8 that I've been adapting to my R10 with a K&F FD-EOS R adapter. When I went to take so moon photos I discovered that it doesn't focus all the way to infinity. I tested with some of my other FD lenses and the issue doesn't seem to be the adapter. Is it worth the time and energy to try adjusting this lens myself? Does anyone have any experience fixing this sort of thing? Paying for a CLA on a lens of this quality seems imprudent.