Hi all, I did some searching but didn't find any specific answers so I thought I would ask. I've purchased some used lenses which are in pretty good shape, but they do appear to be dusty inside. What is the best way to solve this? I had a friend recommend sending them off to be taken apart and cleaned. Is this a viable solution? I don't want to spend a ton of money, however, I'm very leery of opening up a lens myself. Any and all suggestions/advice are welcome.