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What should one look for when buying a used lens?
I am going to buy second hand AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II. The price difference is noticable so I would like to take a chance. But before that I want to know how to test it against apparent demages, maybe scratches, motor/mechanical issues. I would really appreciate if someone could give me couple steps which will show apparent issues.