"Todays" coatings ARE much harder. Any contact will still degrade the coating, granted, to a lesser degree than before, but it is still VERY advisable NOT to clean the lens if at all possible.Originally Posted by Gerald Koch
I remember one instance, where I found a Multi-coated Heliopan filter, in a "Bargain Box", complete with a price sticker ($15) smack-dab in the middle of the glass (and coating). A helpful (at least well-meaning) clerk proceeded to remove the offending sticker ... and *grind away* at the adhesive residue with a dry paper towel.
I think it took me about an hour to un-clench my teeth.
There is an extensive sub-market for "miracle lens cleaning tissues/ fluids". I know not what course of action others may take, but as for me ... surgical cotton, distilled water, and a nearly complete lack of pressure ... once a year, if I cannot avoid it. I consider NOTHING to be "safe".