Poisson Du Jour
Member
A US camera tech by the name of Tomosy, the author of several books on how to fix Nikon, and Leica, and others, uses and recommends..... wait for it..... are you ready....... deep breath..... Windex !
I tried it and it works, and the lense still has its coatings.
There is no risk in using Windex for cleaning any class, certainly not coated and/or multicoated lenses (I clean my Pentax 67 focusing screen and mirror with it). I have had bigger trouble using Kodak's proprietary one-drop lens cleaner. For several decades I carried a small atomiser bottle of it around in my pack until losing it . I switched to single-use pad cleaners (ethanol + water); work the same. The B+W filters are the easiest of all to clean, with HMC Hoya glass not far behind. The biggest mistake I see people make is rubbing any filter without first brushing off any visible surface dirt. Coated or not, dirt will scratch the filter, so that brushing step is first and foremost.