Notes about the Hoya physicial filter only. I've used many of these in the past, but not anymore. First, the aluminum rings seize up (as was mentioned by others - and same in use for me) and can be a real pain. I only use filters with brass rings now - almost exclusively B+W - these have been fantastic. Secondly, I don't care for the MC coating on the Hoyas. In my experience, any water, or moisture contact on their MC surfaces...creates the typical MC irridescent markings...which require immediate cleaning....AND their MC coatings also won't clean easily unless you use Formula MC...minor water spotting on the B+W can be cleaned with lens cloths, such as Kinetronics. I have found that the MC coatings on Hoyas...are more fragile than the B+W as well. I have had one Hoya come apart as well.