Do you all have an issue with your Sigma Lenses? Im on a 4 year old 18-200 and the focusing and zoom rings have white powdery stuff which is tough to wipe away due to it's rubber texture. It's not fungus and i can confirm it's dirt. Do you all have similar problems? Im not sure if other Siggy lenses use the same rubber or not.
Also to note, do u feel that sigma lenses' body, u can scratch it and it gets very visible white line?