I love the 5-stop variable ND and CPL filter, which has numbers 1-5 to indicate the degree of ND stops (rather than guessing). The CPL is working as expected at the zero setting. It takes some time to get used to this combined VND + CPL (no problemo!).

The CPL filter from K&F comes in such an attractive packaging that you can immediately conclude that you have something really high-quality in your hand.
In the box you will find a noble-looking case with a magnetic closure, which protects the filter very well.

This CPL filter is "slim", which has the small disadvantage that you can't hold it a little harder when turning.
Which brings us to the only small point of criticism on my part.

Otherwise you get a very high-quality CPL filter here, which fulfills its purpose perfectly, namely to reduce or prevent reflections, which makes the photos appear richer in contrast and more interesting in color as soon as they are taken.
In post-processing, there are limits in this respect, and quite apart from that, I very often save myself post-processing because the photos simply come out of the camera in a more harmonious way and without looking artificial.

The quality is impeccable, the filter itself is of very high quality.
The image quality is perfect, no color fringes or distortions.

For that 5 stars.
A filter that I absolutely recommend!

Anyone who likes to take photos knows what an ND filter is used for. Since my focus is landscape photography, I can't avoid working with such filters. I ordered this from K&F for my full-frame camera. I was just fed up with always filling my backpack with ND filters of different strengths. The Nano-X Pro was just what I needed. In order to use it on several lenses, I have it in the size 77 mm. ordered. I then work with step-up rings so that I can also use it on smaller lenses. To put it bluntly: I was impressed by the optical quality and the quality of the images! The processing is excellent and very successful. The lens thread is very cleanly cut. The filter can be adjusted from ND 2 to ND 32. The larger steps (f-stops) are marked on the ring and are easy to read. It can also only be rotated in this range from 1-5. It doesn't go below or above. So you always know what you have set by the stop. The 77 mm. Ring weighs 93 grams on my kitchen scale. Everything is massive and feels very good. The adjustment runs well with slight resistance. That's how it should be. The optical quality is absolutely error-free and the filter delivers top quality even in difficult lighting conditions. I did not notice any chromatic aberration or color gradients into green, magenta or anywhere else with pixel peeping. The quality of the filter is unsurpassed even with foliage or fir trees against the light and with reflections from dew. Finally an ND filter that does justice to my limited lenses and the full-frame sensor. The frame thickness with thread is only 9 mm. Without thread 0.63 mm. This means that the filter can also be used on wide-angle lenses without edge shadowing. Thanks to the two screwed brass handles and the ribbing of the ring, the filter can be adjusted very sensitively. Conclusion: K&F Concept has delivered a top filter here. What good is it if you put thousands into lenses and then bad filters make the job difficult or lead to lousy results? Clear 5 stars+ from me. I hope this is useful for your purchase decision. The price is also put into perspective because you save at least 4 ND filters. Thanks to the two screwed brass handles and the ribbing of the ring, the filter can be adjusted very sensitively. Conclusion: K&F Concept has delivered a top filter here. What good is it if you put thousands into lenses and then bad filters make the job difficult or lead to lousy results? Clear 5 stars+ from me. I hope this is useful for your purchase decision. The price is also put into perspective because you save at least 4 ND filters. Thanks to the two screwed brass handles and the ribbing of the ring, the filter can be adjusted very sensitively. Conclusion: K&F Concept has delivered a top filter here. What good is it if you put thousands into lenses and then bad filters make the job difficult or lead to lousy results? Clear 5 stars+ from me. I hope this is useful for your purchase decision. The price is also put into perspective because you save at least 4 ND filters.

Appearance
as soon as I opened the package, I slowly realized that the price was not only influenced by the polarizer itself. The presentation and packaging are reminiscent of a design product. The polarizing filter comes in a stylish slipcase with a magnetically lockable case. In theory, you could also use the included foldable stand to set up the packaging like a picture frame. Not an option for me personally, but you have to admit that the developers of the packaging went through the design concept from start to finish. It could hardly be more elegant.
Personally, I would still prefer a robust hard case, but that's a matter of taste.

To the filter:
I use my polarizing filters mainly in product photography and occasionally in real estate photography, mainly to combat reflections or to partially eliminate them. Anything I do right when I'm shooting takes less time later in post-processing. As you can see on the test images, you can keep surface reflections in check with a polarizing filter. In the meantime, reflections can also be reduced better with software, but you get easier and better results with a polarizing filter. A polarizing filter is still a must-have in some areas of application.
The Nano X-Pro achieved very good results in my test and can keep up well with my existing polarizing filter.
I haven't been able to test how well it reduces flares and ghosting, as I'm currently photographing very little landscape and outdoor scenes. For future outdoor use, it comes with the luggage.
What I don't like is that the filter ring is a bit too cumbersome to turn. This bothers me, especially when it comes to freehand photography, which I do a lot. On the other hand, a ring that moves too easily is not good either. When the camera is on the tripod, the somewhat difficult turning doesn't bother me at all. As you can see, it's a matter of taste and basically not a negative point.

Overall, a very high-quality polarizing filter that is very well made and works very well. On very tough photo trips, I would either pack it in a different case, otherwise I would be too worried about the expensive piece.

The K&F Concept filter arrives safely packed here. It comes with a duster and a bag for storage. The processing of the filter is really first class. High-quality materials, super handling, perfect fit and not too heavy on the lens or in your hand. The filter is simply attached to the lens using a rotating mechanism. The filter conjures up wonderful pictures that you don't have to rework. The price is certainly a deterrent at first - but you get one of the best filters on the market here in my opinion. Professionals MUST strike, amateur photographers CAN strike without hesitation

I have extensively tested this "K&F Concept Nano-X PRO series polarizing filter" with my two 67mm Sony lenses (85mm + 24mm focal length) and would like to share my experiences today:

The packaging of the filter is impressive, because "K&F" has packaged this "Pro" filter in a very attractive and high-quality way. The scope of delivery includes a bag with parts made of leather, which is softly lined on the inside and is used to store the filter. In addition, there is an extra packed cleaning cloth. The bag has a magnetic closure and is very well made all around. The filter itself is also very well made, it has a brass frame and can be easily screwed onto my two lenses. Turning the filter to adjust it also works well. Due to its slim design, the filter does not apply too much to the lens.

The surface of the polarizing filter has a 36-layer nano-coating on both sides, making it waterproof, dirt-resistant and scratch-resistant. The coating makes the filter robust and I assume that this means that it is durable and that I can shoot with it for a long time. I am also completely satisfied with the properties of the filter, it reduces reflections (e.g. in water) by eliminating polarization by around 99% and the contrast of the image (which is easy to see in photos of sky/clouds) is increased.

I have already photographed the landscape with the filter and I am very satisfied with the image quality. I have not noticed any visual impairments from using the filter. I can for the "K&F Concept Nano-X PRO series polarizing filter"

If I'm honest, I've always relied on established brand manufacturers such as e.g. B&W or Rodenstock set. Although I also have a few filters from Kase and K&F in my inventory, I didn't really have Asian manufacturers on the screen when it came to filters.
And that's exactly what K&F wants to change with the Nano-X Pro series.
K&F has meanwhile gained a pretty good reputation in the circles of photographers and this is not least due to the very interesting price-performance ratio which K&F products usually offer .
And now K&F seems to be reaching for the stars and with the Concept Nano-X PRO series they also want to reach the part of the customers who rely on high-quality products and are willing to dig deep into their pockets accordingly.
I tried to find out whether this works with the Nano-X PRO CPL polarizing filter.

As already mentioned, K&F wants to reach the pro users with the Concept Nano-X PRO series and they usually rely on filters from well-known brands and then charge a correspondingly high price for them.
And that K&F is quite capable of producing good filters, I could already see that when trying out the magnetic set and also some plate filters. Of course you had to show a little willingness to compromise here and there, but that was quite bearable, especially given that the filters had previously been in the cheap segment.
This looks completely different with the Nano-X PRO series, here K&F has to deliver unconditionally if they want to do justice to the price.
And yes, they do... starting with the materials, the processing and the quality of the coating, with the Nano-X PRO series, K&F no longer makes any compromises and shows what is technically possible. Gone are the days of stiff threads or seized filters! The ultra-precisely manufactured brass mounts of the Nano-X Pro series run butter-soft and convey the feel of a Peter McKinnon Polar Pro filter. No, that's not blasphemy, comparing these outrageously expensive premium filters with a K&F product. Quite the opposite, it actually
shows only very clear what the engineers at K&F are capable of if you give them free rein

to the filter itself...
I don't want to go into too much detail about the function of a polarizing filter here, that should actually be clear and also the fact that the polarizing filter is one of the filters whose effect cannot be added later in post-processing. It is therefore often said that a polarizing filter is the first and often the only filter that you really need.
The K&F CPL polarizing filter from the Nano-X series tested here plays in a qualitative league with the established brands and must don't hide behind them in any aspect. You don't have to compromise in any category here, really in any. I've never had such a good polarizing filter in my hands, and I'm saying that even though I have an outrageously expensive polarizing filter in stock, both from Rodenstock and from Kase.
The K&F runs so smoothly as if ball bearings were installed and thanks to the milled, really non-slip edge, the filter can also be gripped very well when turning. Of course, an attached lens hood makes it difficult to turn the filter, but that's not a fault with the filter! This is the case with every adjustable filter and many of my lenses have a kind of window in the lens hood for exactly this purpose, through which you can access the filter and adjust it without having to reach through the lens hood from the front.

The K&F also plays at the highest level optically and I could not find any negative effects on the finished picture. It does not visibly distort colors, nor does it significantly increase susceptibility to flares and ghosting. The only noticeable difference, the K&F eats a few more EVs of light, like my Rodenstock polarizing filter, and the tint is about the same as my Kase polarizing filter.
That is of course a matter of taste and one likes very translucent filters and the other likes it to be a little more tinted. Therefore I weigh this point, which K&F does not see as a negative point on the subject of packaging

...
Personally, I prefer a narrow, light plastic case, like these super noble magnetic closure bags used by K&F, but even there you can see the innovative strength that prevails at K&F and the incredible value that K&F places on details. Since I like this kind of thing very much and place a lot of value on small, useful details, K&F already gets a few bonus points from me for the packaging.
If there really is someone who uses the box as a picture frame, as K&F intended, dare that To be honest, I doubt it, but ok, the idea is very nice and a picture frame support that can be folded in origami style is in the box under the filter and cleaning cloth, already in summary

...
Uncompromising, from start to finish, so that with the K&F Nano-X Pro, you don't need to ask yourself whether there might be a better filter, just how to explain this issue at home in the most gentle way

The gray filter is delivered in leather transport packaging, which is closed with a magnet. The filter itself weighs 92g (77mm) and is easy to unscrew. The filter can be turned extremely easily thanks to the two yellow "handles". Very smooth-running. Since there are two handles, one of them is always easy to reach, whether you are right-handed or left-handed. I have not yet had the opportunity to use it in an extreme situation where the filter would really be necessary. The weather hasn't played along for weeks, so I was only able to carry out a few tests in which the filter wasn't really necessary. I was happy with the results and couldn't see anything negative.

First of all, I was quite impressed with the packaging that this filter came in.

It's good to see that at this price point, exceptional quality packaging is used to protect this gear, which is relatively expensive for what it is. It's just a piece of glass, isn't it? Well, actually no. I found it worked best, at least in my application, for reducing glare from windows, windshields, water, and basically anything that has a reflection.

I can shoot video on top of a car and eliminate the distracting elements of passing trees or just the environment the car is in.

This is truly a beautiful piece of glass and you don't have to worry about your footage or photos being 'downgraded'. It's definitely more of an upgrade.

Got this to improve the image quality when I'm out in the evening to photograph the beach along the coast here. The filter was really easy to attach to my Canon EF 70-200 2.8L lens and is very easy to maintain. The pictures turned out stunning, especially from the water. I'm in love with this lens filter which is my new daily driver. Value.