Not recommended, photos appear out of focus

I can in no way recommend, photos are clearly blurred esp. in use of polarizing filters. The courses go but still not worth it because you want to have the highest possible sharpness yes. Better take a polarizing filter Hoya and then curves eg do with Color Effex in the mail.

Especially bad the quality is when you use multiple filters simultaneously therefore definitely not recommended.

Good glass needs good filter, is just how it is.