Admittedly, the magnetic filter system is not entirely new and I can't say who copied it from whom, but I am already familiar with K&F through very good lens adapters and solid tripods. And since I have been flirting with magnetic round filters for a long time, but the prices for such a system seemed too steep, I was of course interested to see that K&F now also offers something like this. Whether the magnetic K&F round filters convinced me or the cheaper one Price here requires too many sacrifices, you can read that in my review...So far I have used screw-in filters from Rodenstock, B+W, Heliopan and Haida. So they're all brands where a filter costs what K&F wants for a complete set including a bag. I was therefore very skeptical about what to expect, also because K&F advertises Schott glass (hardened and therefore very robust) and 16-fold nano sealing. That sounds surprisingly good at first, but in practice it doesn't mean anything because in the end it's always about the optical performance, no matter how great the handling advantages are. Which is actually better, round filters or a 100mm filter system with plate filters, this question This is certainly a question that everyone who gets into the subject of filter photography will ask themselves. Until now, round filters always had to be screwed into the front thread of the lens, which can be very complicated depending on the situation and the lens. Even when combining several filters, each one had to be screwed onto the previous one individually, which in turn quickly leads to vignetting, at least whenever the filters have the same diameter as the lens. Therefore, a 100mm or even 150mm plate filter system has always been the first choice for professionals. Now the topic of round filters has been completely revolutionized by the introduction of magnetic filters. Changing filters has become so easy that the handling advantage of the plate filters no longer exists for me. On the contrary, with plate filters I always have to be extremely careful not to accidentally grab them (fingerprints) and unfortunately that happens very quickly when you take them out of your bag or put them in the holder. This is different here with a round filter with its metal frame. Of course, it can happen that you accidentally touch the glass, but the risk is significantly smaller and round filters are much more robust. Anyone who has ever dropped a plate filter will know what I mean