I have several Bay I "Rollei" Brand filters for my Rolleicord Va. Several questions . . . 1. Are the Rollei Brand filters quality and good for BW photography? 2. Are there better non-Rollei brand filters out there? Where can you get them? 3. What is the best way to clean Rollei filters w/ dust and hard to remove micro-debris? 4. I noticed on one of the filters (orange) -- there are tiny pinhole (no filter color, just clear transparency). Will this have any affect on the neg? Thanks!