Relatively new to CZ lenses, but have an 80-300 F4 Vario Sonnar which unfortunately picked up a faint scratch in the coating on the front element of about a quarter inch in the Middle East last year. Have not seen any effect on my pictures yet. Wonder if this is a big problem, and if its worth sending back for repair. I have very little in the lens, and some have told me this will never really be a problem. Thanks for any advice.