iam sure this is a very common problem most of us faced.
i have a regular lens which i used more often.
as we know during hot weather with sweaty palms turning the black rubber to zoom or focus,it will leave those white marks behind after the sweat is dry.
i search on Lens coat but seems like not all lens model will be covered on the zoom or focus rubber ring.
is there any products that can help to prevent such problem like gloves,cover...etc?
and also for those white markings,how do i clean it off to make it look like a new one?