I use blower with attached-brush lightly at the same time(to :bigeyesrevent any scratches coz by any fine particles on the surface, then, just use Lenspen will do the job:kissonly lenspen=normal & mini versions, so far, maybe its B+W filters, coz many yrs-abt 9yrs ago was using Hoya but due to:sweat: "aiya & aiyo":thumbsd: then changed all to B+W liao:thumbsup
Because MRC coating of B+W filter is superb and smooth, so no problem cleaning. If you have Hoya filter, you know how difficult is to clean fingerprint on hoya filter. With B+W filter, its so easy... Just use microfiber cloth. Last time I use Hoya filter, but after I try B+W filter, I change all my filter to B+W filter.