CPL filter is a necessary add-on if I want to get good quality pictures is bright sunlight so I bought one. Then I realised that in low-light conditions the recorded videos are terrible. I think that the problem origins from the fact that E serie has an aperture f1.8 which is too narrow for putting CPL lens on it in low-light conditions. According to basic principles of photography the less light and/or the narrower aperture you have the longer time needed to take a picture. If I put CPL filter on, the actual aperture changes from 1.8 to 2.3-2.4 which is simply not enough to take right exposured pictures fast enough and to avoid blure. That is something you cannot fix by settings. If I set exposition to -1 (or lower) I end up with a dark, under exposed video, still not good for reading details. Some competitors have f1.3 front lens so they easily can add CPL filter on it, they still have a total aperture (STOP value) of 1.8-1.9 which is similar value E serie has without CPL filter. Taking CPL filter off and putting back on everytime when circumstances change is absurd. Pity about this design flaw!