Do you know how to clean the camera lens? If you have not read the user guides then you better don't simply wipe your camera lens with tissue or hard cloth. When i just got my new lens back, i was really silly enough to use tissue wipe the dust off, fortunately i read a very important sentence from the magazine that the lens also will get scratched even just simply wiped by soft tissue. If you love your lens, better buy a chamois skin for cleaning the lens, Hakuba "Special Chamois Skin" is quite a good choice too. Check it out.