Admittedly, the system of magnetic filters is not entirely new and I cannot say who copied from whom, but I already know K&F from their very good lens adapters and solid tripods. And since I've been flirting with magnetic round filters for a long time, but up to now the prices for such a system have seemed too steep to me, I was of course interested that K&F now also offers something like this.
You can read in my review whether the magnetic K&F round filters were able to convince me or whether the low price demands too many sacrifices here...

So far I have used screw-in filters from Rodenstock, B+W, Heliopan and Haida. So everything is more of a brand where a filter likes to cost what K&F wants here for a complete set including a bag. I was therefore very skeptical about what to expect, also because K&F advertises with Schott glass (hardened and therefore very robust) and 16-fold nano sealing. That sounds surprisingly good at first, but it doesn't have to mean anything in practice, because in the end it's always the optical performance that counts, no matter how great the handling advantages are.

Which is actually better, round filters or a 100mm filter system with plate filters, this question will certainly be asked by everyone who gets into the subject of filter photography. So far, round filters have always had to be screwed into the front thread of the lens, which can be very cumbersome depending on the situation and the lens. Even when several filters were combined, each one had to be screwed onto the previous one individually, which in turn very 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.

But now the topic of round filters has been revolutionized by the introduction of magnetic filters. Changing filters has become so simple that the handling advantage of 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 that unfortunately happens very quickly when taking them out of the bag or putting them in the holder. Unlike here with a round filter with its metal frame. Of course it can also happen here that you accidentally touch the glass, but the risk is much smaller and round filters are much more robust. Anyone who has ever dropped a plate filter will know what I mean