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'.

This is a really, really nice CPL filter. It has a very slim design so it doesn't result in any vignetting, even while using may long telephoto lens.

Threads onto my lens easily without issue.

Adjustment of the polarizer is smooth and predictable.

There's no color shift or any other artifacts from the filter. Just crisp images with accurate color.

The filter comes with a nice fabric storage case, along with a microfiber cleaning cloth.

There's also a little instruction card that details how to use the box the filter was packaged in as a photo frame. Kinda kitschy but whatever. I just tossed it.

Great quality though.

RECOMMENDED>

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.

I tested the K&F Concept Nano-X PRO series polarizer 67mm with the Sony A7RII on a Sony SEL-20F18G. I use polarizing filters for 99% in landscape photography. Since the effect is virtually impossible to simulate in post-processing, a polarizing filter, in addition to grey filters, is one of the only material filters that I regularly use.

The K & F is one of the slim filters. This can prevent vignetting in an extremely wide angle, but the slim frame makes handling much more difficult. Due to the design, this is the case with almost all manufacturers. After all, the filter has a threaded socket at the front, so that several filters can be screwed one behind the other. Depending on the type, the lens hood and lens cap can also be fitted. The filter comes in a high-quality, sturdy bag with magnetic closure. As a little gimmick, the manufacturer also includes a microfiber cloth for cleaning.

The thread can be unscrewed cleanly. The rotating frame runs smoothly and smoothly. The slim design makes handling sometimes very difficult. On the one hand, you have to be careful not to screw the filter too hard onto the lens, otherwise loosening it by hand will be difficult. On the other hand, when turning the filter counterclockwise, there is a risk of unintentionally loosening the filter if it is not screwed on firmly enough. With the lens hood attached, operation is also no longer possible.

The glasses come from the Japanese house Asahi Glass and appear to have a high-quality finish. I was unable to detect any loss of sharpness even at extreme magnification. I was able to notice a slight color deviation into reddish. However, this is really barely noticeable. Since my used lens is not susceptible to lensflares, I was happy that there was no deterioration with the filter on. The filter absorbs almost exactly one f-stop of light, which is a very good value. The filter effect is good, but I honestly didn't expect anything else in this price range.

In my attached pictures, you can see the result with strong backlight, both with and without filters. I couldn't find any differences in quality or lensflares here. You can easily see the filter effect on the leaves on the other two pictures. Here, sunlight falls on the shrubs at an angle of about 90 degrees. The polarization effect is clear. The white balance was set manually to daylight for all shots. The only very slight color shift is barely visible here.

So far, I haven't had K&F Concept on my screen in this price range. The results of the filter are first-class and do not reduce the quality of my high-quality lenses. Unfortunately, you have to live with the somewhat difficult handling of this design, and K&F is not reinventing the wheel here either. However, I give the full five stars for optical performance.

First and foremost, the polarizing filter reduces reflections and light reflections. The image can therefore be freed from disturbing elements even while taking pictures. Even if you call yourself a “Photoshop professional,” you can never achieve the same results in post-processing on a PC as with a polarizing filter. These filters can be used in various situations. In addition to the ND filter and gray gradient filter, it is one of the most popular little helpers, especially in landscape photography or simply outdoors. A few examples:
You want to photograph a frog in a puddle. However, the sun shines so strongly that the picture becomes bright and the sun is reflected in the puddle. The actual motif — the frog — is shown far too little. It is precisely in such cases that a polarization filter is used, which allows the sun to be removed almost completely from the image. The viewer is then fully focused on the actual subject again. In general, the polarizing filter is often used for reflective water surfaces.
Every object reflects light. Otherwise, it wouldn't even be visible to the human eye. Sometimes, however, the reflection is so strong that the colors are distorted. A lush green meadow, for example, can suddenly look pale and boring because the color intensity decreases due to the strong reflection of light. The polarizing filter also helps here. It can therefore not only reduce reflections, but also give a motif its strong, natural color back.
The K&F Concept Nano-X PRO series polarizing filter has a very high-quality finish and could be easily attached to my lens.
I took two pictures on the Schnell, you can see the difference. The images have not been processed.
The filter comes in an elegant case, including a cleaning cloth. The magnetic closure is great.
The price is completely okay, I can recommend this filter!

K&F Concept Nano-X PRO Serie Polfilter 67mm

Von der Verpackung bis zum fertigem Bild, alles auf höchstem Niveaus. Qualität und Verarbeitung des Filters ist top top top. Er lässt sich sanft und ohne zu verkannten in das Objektivgewinde eindrehen. Der Drehmechanismus hat einen guten Widerstand und lässt sich perfekt einstellen. Die Bildergebnisse überzeugen und ich konnte keine negativen Effekte feststellen. (Farbsäume oder ähnliches)

Wie bewertet man nun den Preis eines solchen Filters? Ich denke Leute mit fotografischer Erfahrung wissen was solch ein hochwertiger Filter kostet. Ich finde der Preis ist durchaus angemessen für den hochwertigen und sehr gut gearbeiteten Filter.

The filter is packaged in a small design object. The bag is well thought out from front to back and is just as well designed. But: a lint-free hard case would be much better. Unfortunately that was nothing.

A filter is always a compromise. I put a layer between the object (light) and the lens. As a result, quality is inevitably lost. In this case, the loss is very low, which speaks for the very good quality of the glass. The reflection of the surfaces is visibly reduced.

The ambitious price matches the performance of the filter. However, I don't use the filter bag, but use a hard plastic box - as always.

I'm really no expert when it comes to filters, but of the dozen or so I own this is far and away the highest quality. You can feel the build quality the moment you screw it to the lens. It's incredibly lightweight but doesn't feel at all flimsy, and the threading allows for super smooth application and removal.

I use polarizing filters more than any other as I live in a country that has near constant sunshine, so I've had plenty of chances to test this filter since I received it. The results have been just as good as I'd expect given the price. This thing beats the pants off my cheaper filters.