I have tested this “K&F Concept Nano-X PRO series polarizing filter” extensively 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 this “Pro” Filter very attractive and well packaged.

You will receive a bag with leather parts, which is softly lined on the inside and is used to store the filter. In addition, an extra packed cleaning cloth is included. 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 also works well. Due to its slim design, the filter also does not apply too much to the lens.

The surface of the polarizing filter has been coated on both sides with a 36-fold nano coating, making it waterproof, dirt-proof and scratch-resistant. The coating makes the filter robust and I assume that this makes it durable and allows me to 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 (easy to see when taking photos of sky/clouds) is also increased.

I've already been shooting in the landscape with the filter, I'm very satisfied with the image quality. I did not notice any visual disturbances caused by the use of the filter. I can recommend the “K&F Concept Nano-X PRO series polarizer”.

Tested for video on my VG30 and works like a charm. It comes with a nice carrying case. Remember: You need to install on the front of your lens and then turn clockwise or counterclockwise so you can align properly and get the elimination of reflection that you are looking for.

I started photography back in the film days, when digital post processing was not an option. Consequently, filters were a must. I have always had circular polarizers available for all of my landscape and outdoor work
glass. The K & F Concepts CP is relatively expensive, but why buy high end lenses and skimp on the filters?
The packaging and presentation is befitting the high quality glass enclosed. This filter is simply the best quality polarizer I have used to date. I highly recommend this item, it is worth the price, and you will not be disappointed.

I had the opportunity to test the polarizing filter from K&F.

Facts:
• Thread size: 67mm
• multi-coating
• waterproof
• incl. bag

The filter is delivered in attractive product packaging. The customer is immediately interested here and wants to get started. The bag that comes with it protects the filter optimally.
It is very robust and scratch-resistant.
It is also very easy to adjust and allows precise adjustment and fixation. The effect that you achieve with this polarizing filter cannot be achieved in post-processing. The filter shows its quality, especially when it comes to reflecting water surfaces.

Overall, I am very satisfied with the result of this filter. It ensures a significant increase in the quality of your images. Clear purchase recommendation from my side.

I've become a big fan of K&F Concept filters. I have quite a few of their ND/VND filters and a Nano-X series CPL filter that is simply excellent. This is my first Nano-X Pro series filter and while the others are high quality this one is on another level entirely.

The filter has a coated CNC machined brass that attaches to my lens smoothly and comes off without binding. It's slim to minimize any possibility of vignetting yet retains front threads to attach other filters. The edges are knurled and move with a slow liquid feel that helps the filter stay adjusted where you want it. The filter has K&F's Nano-X 36 layer MRC coating that resists glare, fingerprints, etc. and makes the filter easier to clean.

It comes in a slim leather case with magnetic clasp and drawstring that lifts the filter up when you pull it - this is a great feature that helps keep fingerprints off the glass.

As with my other K&F filters this one is extremely neutral without any color cast that I can detect. It has replaced my older B+W CPL filter in my bag and takes the place of my Freewell magnetic ND system when I want to travel light. It's K&F highest-end filter and compared to the competition it's cheaper and better quality making it a fantastic all-around value. Highly recommended.

First off, I'm a fan of K&F's products, I try to use them as much as I can during photo sessions, since they just give good consistent results.

However, the ONE complaint I've always had, is that K&F's product line was quite limited to low to mid range products. Don't get me wrong, they are amazing for what they are.. and I LOVE having them on location. But, as with any product I use in the field, they're often NOT the same products I will used in a fully controlled environment. In a perfect world, I would be able to take all of my studio gear on location, and not have to worry about potential damage to my gear.

To that end, K&F's mid-range type of filters and equipment have worked extremely well..

However.. I've always wondered.. what if my preferred manufacturers actually produced higher end gear.. would the results be as good? Better? What might I be missing, by taking certain types of gear, over others?

When I saw that K&F was producing a 'Nano' sort of lineup, a while ago, I was excited.. but also somewhat concerned... I already had my high end filters that I would use on special occasions, and for studio work... would K&F be able to actually meet that quality? If so.. could I stop buying gear from manufacturers that I didn't want to use, due to their awful customer support practices?

When I saw this filter pop up on my recommended feed.. my curiosity got the better of me, and I had to order it.

I grabbed the 82mm version, since my primary workhorse lenses are 82mm. Sigma 24-70mm f/2.8 DG DN Art, is commonly my 'Go To', though having rented and used a Tamron 35-150mm f/2-2.8 Di III, a few times, now.. and having it on my wish list.. both use 82mm filters.

After using it for a couple of sessions, now... both studio and on location, I have some initial short term thoughts:

Exposure change is minimal. - This is a big deal, since so many 'cost effective' polarizers will often drastically impact exposure. I've seen some filter change the EV by as much as a full stop. At that point, a CPL is operating more like a slight ND filter, and is not really optimal if all you're wanting is glare reduction. This one, I would say reduced the EV by roughly 1/8th of a stop when installed.

Color shift also seems to be minimal, if there is any at all - CPLs are also often plagued with the problem of changing the color of a scene, when they're applied, and in the case of variable polarizers, you may even experience a color shift while adjusting the amount of filtering being applied. This isn't ideal, as it just means you're going to have to do more color adjustment in post. Now, that said, keep in mind, the way a variable CPL works, if that if you reduce the glare from a source that is producing a color cast, you WILL have some color shift. This is just the nature of light.. similar to using a gold colored reflector for a subject illumination. If you remove the gold color from the reflector, there WILL be a color change. This is not the same as a filter created color shift.

Distortion seems to be non-existent - This is ANOTHER problem that so many filters (in general) have, and can often be so slight, as to not be seen until you're working with your files (RAW or otherwise) in post. I've seen a large number of filters absolutely ruin photos in the past, so it's something I tend to be VERY twitchy about. This filter seems to have no distortion at all. I'm EXTREMELY happy for that.

Quality & build - This filter has 2 parts to it. When I say that, I don't mean there's 2 physical parts that you have to attach... just that there is the static mount, that attaches to the end of the lens, and the adjustable portion that floats and rotates on the end. The static mount is actually a bit on the small side, which means if you are going to be attaching this to your lens, with any bit of snugness, you may want to use a filter tool for it.

NOTE: This filter does NOT have a forward facing threaded mount. If you use a lens hood that attached via the filter threads, it WILL NOT WORK with this filter. Additionally, the lack of a forward thread also means you cannot stack this filter with others, OR you will want to use it as your last filter in the stack. I know.. there is some photographer out there, right now, reading this, who is screaming that you shouldn't stack filters, ever.. but you saying that, doesn't change the fact that there ARE those that do. If you DO still want to use the CPL as a middle filter, you're going to need to get some external mount adapters to do so.

Case - The case the filter comes in, is actually a nice little leather and denim case, with a pull string on the side, that will push the filter out for you. My only gripe with this case, as with so many others, is that it'd be nice if the case had a small insert for a label. When carrying around a kit of filters, and you're operating in lower light conditions, it's often a pain to read the edges of the filters to determine which one you're grabbing. Adding a small label pouch would be an awesome addition.

Un-important - The packaging of the filter is quite nice, having a sturdy foam framed box, and including a microfiber cloth is a nice touch. The fact that the box turns into a 'picture frame' is gimmicky, and borderline insulting, as if the average person buying this were a child, who may become super excited over using a dense foam-board package as a photo frame. It's a $180 lens filter... the person buying this isn't going to spend that, and then not buy a decent frame for any photos they produce. This sort of marketing gimmick might work for those individuals buying a $20 CPL for their instagram photos.. but this filter is clearly aimed at the higher end photographer.

So.. that brings us to the big question.. how are the results? Honestly, I can't find a reason to complain at all. Colors come through as expected, no distortion, and absolutely no image reduction. The smaller mount point on the front lens element keeps flaring down to a minimal, and produces nice, crisp fantastic images.

The variable polarization works as expected, but I would have liked to see it spread a bit more evenly around the lens. Right now, when I turn the adjustment ring, there seems to be an awful lot of lack of polarization for a good amount of the filter, before the polarization kicks in, quickly.. a more gradual approach would have been preferred, BUT, that's nothing different from the current high end CPL I'd been using, either.

Which brings me to the price... at the currently listed price of $180, this filter is squarely in the upper end pricing for a CPL, which is an area that is already a rough spot to be in, since CPLs usually start to lose their price to performance around the $100-150 range. The $180 range now places you clearly in the range of B+W, Zeiss, and Hoya... 3 of the big names that dominate that market spot. It DOES perform on par to may of those products, but then again, you also have companies like PolarPro that have been making leaps and bound in that area, too, with the latter being VERY aggressive in their price to performance. I've had experience with all of the above, and while I really like K&F's customer service, and the fact that they're a LITTLE cheaper than many of the aforementioned brands, it doesn't change the fact that they MIGHT be pricing themselves out of the competition. If this filter was aimed at a lower price point, say $130-150, it might be an easier pill to swallow, especially if you're the type that wants a separate filter for every lens in your kit (as opposed to using a step down/up filter set).

That said, so far I'm immensely happy with the results I'm seeing with this CPL, and I'm cautiously optimistic that my long term experience will keep me comfortable with this CPL... time will tell, but for now, I'm cautiously recommending it, even at its current price.

Since the filter was positioned as a member of their flagship lens filter line I definitely had already high expectations in the K&F Concept Nano-X PRO CPL filter.

It certainly made its first impression while unboxing it -- it comes in a stylish box and inside that box is an elegant leather filter carry case.

But more important is of course what it delivers in front of a lens. And that is indeed amazing: I tested it on different lenses, a 70-200 mm lens and on a 35mm. Based on physics of a CPL filter in general it is not advised to go wider than 24mm.

I found no distortion problem; reflection and glare get well mitigated; no vignetting or spots, or dark areas detected within the focal lengths mentioned. Also, of course, keeping a certain angle towards the sun will determine the outcome.

That is definitely a high-end filter and I think K&F has made it into the professional market and its expectations.
I was happy with the test results and can recommend this filter, it is a well-worth investment, and my motto is 'better no filter at all than a cheap and bad filter'.

I've been a fan of K&F Concept for a long time and have a lot of filters. Especially in the beginning, the cheap products were a real boon for my wallet. I simply couldn't afford expensive polarizing filters, ND filters, or adapters. However, they impressively demonstrate that K&F Concept can also be absolutely high-quality with this filter series.

I can report that just unpacking the filters is a real pleasure. Although this doesn't count directly into the review, it immediately gives off a completely different feeling than with the brand's other product series. It continues with a very attractive and haptically convincing case, which allows the filter to be removed via a tab.

But now on to the filter itself. I already have several polarizing filters in use, but none of these filters really convinced me as much as the Nano-X PRO. The workmanship is simply excellent, the weight is comfortable in the hand and the thread is fun - when screwing on and even unscrewing again. Most people will be familiar with it, cheap filters like to stay in place. The optical performance, which is ultimately important, is great. Reflections are skilfully filtered and there is also no distortion of the actual image. The look that is created is simply great. When you do some magic in post-processing, photos of cars simply look amazing, a completely different level. I can therefore make my recommendation without hesitation.

This filter does a wonderful job of reducing glare and making blue skies richer.

Transparency notice:
The product was made available to me free of charge as an evaluation sample, free of any influence or expectations. My review is based solely on my personal assessment and experience of using the product.

Review:
For quick readers, I'll preface my review, below I'll explain the details of my decision making, my impressions of the product.

I only make a minimal deduction of points and award 5 stars, i.e. 5 stars rounded up.

My only criticism is that the filter rotates slightly too slowly, i.e. its operation when it is screwed onto the lens, but I hope that will subside a bit over time. No, the turn isn't slow, but it's a bit tough, I expect a slightly smoother movement here.

Workmanship:
The slim frame is of very good quality, precisely processed and painted. I like slim filters, they build up less high on the lens and therefore do not limit its viewing angle, especially with a strong wide angle.

Slim filters can have the disadvantage of being more difficult to handle, as the grip ring is very thin. It is helpful here if it is handy and that is exactly what the K&F filter is.

I can grasp the filter very well and see no problem even with wet fingers.

The glass in the filter is of very high quality, optical glass, very precisely processed and absolutely flat, and has also been coated several times.

First, pick up the filter and look through it, preferably against strong contrasts and straight lines, such as a façade.

Here you can see that you don't see any glitches. I don't notice any distortion, the image is absolutely flat, over the entire surface of the filter, and I don't see any color distortions, I'm very satisfied.

It looks no different when I screw the filter onto my lens, but here is another aspect, possible reflections, but that is exactly what a polarization filter is supposed to eliminate.

In terms of image effect, this is absolutely undisputed, whether on a water surface or on windows, reflections are suppressed very well, as expected. But there is another aspect and that is the reflections on and behind the filter towards the lens when backlight comes in at an acute angle due to small punctual light sources. I don't see any reflections here, which speaks for the very good coating and glass quality of the filter.

I am very pleasantly surprised by the packaging of the filter and that starts with the attractive outer packaging in a high-quality slipcase.

It contains a flip case with magnetic closure, it is very decorative and practical, much higher quality and more elegant than the commonly used plastic boxes.

Conclusion: The K&F polarizing filter is not
a bargain at just under €150, but it is inexpensive in the sense of the word and is clearly placed in the premium segment. The processing quality itself is just as impeccable as the optical imaging performance on the lens. The included case is very attractive.

Only the somewhat slow adjustment of the orientation minimally disturbs the overall impression, so I subtract half a star for this. In the overall impression, this only plays a subordinate role and leads me to an almost unrestricted purchase recommendation.

Thank you so much for your attention when reading my review. If you'd like, feel free to give me some feedback, I'd be happy to hear from you.