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

More magnetic filters please

Finally after 3 products from K&F I found what I was after, the 1st set, screw on one's are good but too fiddly for me, 2nd, square set again great but can't fit lens cap & not enough filters in the range, & finally this set, absolutely fantastic, everything I was wanting, more ND filters will be added to the range, magnet is good, filters have next no colour cast, the CPL is great to use, quick & easy changes with no fuss, compare these with more expensive brands & you will wonder why you spent all that money, these do everything...if not a little better than a few well known products out there, I am so pleased with these I am going to feature them in my YouTube channel.... Moto Tripper UK.

Been wanting to try these K&F Concept Magnetic Filters since they were announced,
I’m glad I purchased these they’re awesome,
Super easy to use and swap when in the field,
Just attach the magnetic ring to your lens and then it’s simply a case of attaching the filters with ease and swapping out,
No hassle of having to screw the filters on and off, this is totally a game changer in my opinion, I own a fair bit of K&F gear and these are great quality as always,
I have the k&f square filter kits but these are way easier,
The supplied case is really nice too,
They’re not cheap but you get what you pay for, I’m overall extremely happy

I am absolutely satisfied with the overall package price-performance is definitely right here the magnet is strong enough and I could not find any gaps as described in other reviews the bag offers good protection and can be easily attached with the double Velcro fastener and the eyelet for a hook I would buy the magnetic filter set again at any time

Molto comodi con il meccanismo magnetico. Più volte quelli a vite mi sono rimasti incastrati nelle lenti. Con il ring magnetico sono veloci da cambiare e usare. Quelli di 82mm sono compatibili con il sistema Kase che offre più scelta di filtri ma a un prezzo più alto. Io ho un mix ora dei due brand e mi trovo bene. Per qualità prezzo i filtri K&F si posizione in un ottimo posto. Io li raccomando vivamente

As a photographer, I use filters, but it's not always easy to put on or take off depending on the situation. But with this system, it becomes so simple that it's almost instantaneous.
The product is of very good construction quality and it comes with a very well made and resistant 4 pocket pouch against possible knocks. It can be attached to the belt with a Velcro. The kit is composed of two screw rings, one UV and one vacuum on which the CPL filter or the ND1000 can be fixed.
I really wanted to go and test this new product. First with the CPL filter alone and then with the CPL filter + the ND1000 together. The results are just astounding. Here are the renderings with the CPL filter on the left and the CPL + ND 1000 on the right. With filters, there is no loss of sharpness, and color drift is almost zero. The CPL filter polarizes perfectly and the ND 1000 filter is very surprising in terms of its performance, it is very thin which limits vignetting, a plus. By using the two together, it is better to avoid ultra wide angle focal lengths, but from 16mm, no worries, you can add them. In addition, they are compatible with my sun visor, I was able to put them on and take them off without having to take them off very easily because the magnetic force is perfectly dosed.
Really very satisfied with this first release, I hope that other intermediate magnetic filters with this system will be released soon to complete the offer.
If there were magnetic lens caps, that would be great.
It is a very good investment and the price is more than correct given the quality and the results obtained.

As a landscape photographer, I found this filter system really interesting. Unlike screw filters, these filters are applied and removed in a fraction of a second, while unlike plate filters they are much less bulky, lighter and, of course, much quicker to install.

PACKAGING AND CARE OF DETAILS

The filters are delivered in a convenient and very well made case with four compartments. The case, in the back, has a hook and loop buckle that we can use to attach it to our tripod or our trousers and, in addition, a metal ring so that it can be attached to our backpack, tripod column or wherever we prefer. Finally, the zip closure of the case is resistant to rain or water infiltration.
The filters are contained and protected individually inside special sachets so as to avoid any potential damage.

CONSTRUCTION

These magnetic filters from the K&F Concept Nano Series are made of optical glass that is perfectly resistant to water, oil and dust. The external frame is in slightly knurled aluminum to allow an excellent grip.
They are extremely thin and, even by mounting all three filters at the same time (UV, CPL and ND1000), the thickness is extremely low.

UV FILTER

In the photographs I took with the UV filter there are no color alterations, no loss of sharpness and details and no dominants of any kind.

POLARIZING FILTER

This polarizing filter provides a pleasant overall contrast to the image, increases the contrast between individual colors and saturates them without overdoing it. In addition, it provides a very slight warm cast which, personally, I do not mind but which is easily corrected in post-production.

All 3 filters for me are very useful. The stand-alone ring however, I'm wasn't sure how much I'll actually use it but surprisingly I just leave it on my lens unless it's pretty bad weather, which in turn I use the UV filter as a protective layer for the glass. Personally, I haven't found the UV filter to do much other than to protect my lens and because the glass of my lens is such high quality I don't leave it on as it could degrade the photos, that's why I use the stand-alone ring. I haven't noticed any degrading when using the UV filter so no complaints. As mentioned earlier, however, I only use it to protect my lens. The CPL filter works wonders and the ND filter is great for long exposer shots. the combination with the magnetic touch make this absolutely flawless. would recommend.

I own quite a few K&F Concept Products. They provide quality products without the hefty price tag we're used to see in the photography world.

Let's talk about the filters individually first. All 3 filters are of top quality, at least on this price point/tier, as we're used to get from K&F Concept products:

-The CPL Filter has no color shifting and performs as expected.
-Same with the ND1000, although i don't use 10-stop filters that often (my most used filter is a VND Nano from K&F Concept) during my test it worked well, no cross present, even while using step-up rings.
-The UV Filter has no color shifting and the main purpose these days of the UV filter is to protect the lens surface, BUT, It is where this VERY MINOR issue this kit has: The magnetic ring holder.

The magnetic ring holder works great with the ND and the CPL, just not as good with the UV Filter, but it is not by ANY MEANS bad or i'd call it unsecure, at least not on the 82mm filter size version, your mileage may vary depending on the kit size you got as the magnetic surface may be different for your version, just the grip doesn't feel as tight as it does with the other two filters and there is a TINY bit of play, but not enough to warrant losing a star over it, i mean if you shake the camera at full strength you may drop it, but on regular usage i do not see it just falling off the ring holder.

As the sum of all parts i'd say this was almost perfect. This kit complements my VND ND2-400 and includes everything i need to cover all my filters along my step-up rings. The UV filter thing doesn't make it lose a star, but maybe half, so i'd say 4.5 but since there's no option for that if i had to decided between 4 or 5 stars, i'll go with 5.