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.

This is a really nice polarizer and it works fantastic, as you would expect at this price point. It really just looks and feels high quality. Just be very careful when installing that you don't crossthread it, because I apparently did and now the filter is stuck on my lens :-( I will be leaving it on all the time because the camera shop I took it into said they are likely to break the filter trying to remove it. I don't think that is a fault of the filter though, just me not paying enough attention when I was putting it on.

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!

I recently purchased the K&F Concept 67mm Circular Polarizers Filter Super Slim with 36 Multi-Layer Coatings and I'm so impressed. It's amazing how much of a difference this filter makes to my photos - in terms of clarity, sharpness and colour vibrancy. It's super slim, yet incredibly strong and durable. I love the 36 multi-layer coatings which give me amazing results every time. The images are crystal clear, thanks to the high definition coating. The colors come out vibrant and the polarizing effects are stunning.

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.

As soon as you unpack it, you notice that this filter is of very high quality, as it comes in high-quality hard cardboard packaging. A very stylish and practical case is also included. The filter itself also looks super high-quality, scratch-resistant and works wonderfully!
It is very easy to screw onto the lens and also rotate it, although this is a bit difficult. But that doesn't mean it slipping either!
The price is quite high, but anyone who is willing to pay that much will have an absolute top product!

I've used ND filters from K&F in the past, so I wasn't surprised by the quality compared to newbies. The filters allow sharp focus without restrictions. Thanks to the really extremely thin glass and the thin frame, there is no cloudiness or dark spots at the edges.

The frame has small brackets so that if you want to readjust it, you don't have fingers in the picture.

The whole thing is rounded off by a nice leather storage pouch. Overall, absolutely great!

While my particular polarizer did seem to have a blemish that caused it to not work with my camera lens, K&F were very quick to offer support and refund my purchase. I value this empathy for the customer very highly and was completely impressed by K&F in that regard.