So for a moment I got confused. I visited B&H in NY and wanted to stock up an some accessories as they are so much cheaper in the US compared to Denmark. So when the friendly sales man asked me if I needed anything else (after having order the Samy FE), I said yes a circular polarizing filter - what size he asked and I said 46mm, I should have said 52mm for my Oly 9-18mm. Didn't realize my mistake before being back in Denmark. So now I have a circular polarizing filter that fits my Pany 20mm and Oly 60mm. The thing is I haven't used it yet, even though I use the Pany 20mm quite a lot. I simply forget to put it on instead of my UV filter. Question: should I just leave the cir pol filter on the Pany 20mm i.e. will I benefit more from having it on constantly or are the times when a circular polarizing filter is a really bad idea? I use the Pany for various things outdoor/indoor, it is my default lens. Is there any use for the cir pol filter for my macro lens? Should I sell it and buy a 52mm for the 9-18mm instead. (I will probably buy a filter for the Oly 9-18mm anyway). So is there any use for circular polarizing filter 46mm?