Anyone who likes photography knows what you use an ND filter for. Since my attention is the landscape photography I can not avoid working with such filters. I ordered this one from K&F for my full frame camera.

I was just tired of filling my backpack with ND filters of different strengths. So the Nano-X Pro came in handy. To use it on several lenses I ordered it in the size 77 mm. I then work with step up rings to be able to use it on smaller lenses.

To say it right away: The optical quality and the quality of the images has flashed me! The workmanship is excellent and very successful. The lens thread is top clean cut.
The filter is adjustable from ND 2 to ND 32. The larger steps (f stops) are marked on the ring and easy to read. It can also only be turned in this range of 1-5. Below or above it does not work. So you always know by the stop what you have set.

The 77 mm. Ring brings 93 gr. on my kitchen scales. Everything is solid and feels very good. The setting runs well with slight resistance. So it should be.

The optical quality is absolutely flawless and even in difficult lighting conditions the filter delivers top. Chromatic aberration or color gradients into the green, magenta or anywhere else I have not been able to determine even when pixel peeping. Even with foliage or firs in backlight and with reflections from dew, the quality of the filter is unsurpassed. Finally a 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. So you can use the filter on wide angle lenses without edge shading.

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 but then bad filters make the work difficult or lead to lousy results? From me clear 5 stars+. I hope this is useful for your purchase decision. Also the price is relative because you save at least 4 ND filters.

I bought this adapter to use Sony A-mount lenses from my Alpha 58 on the BlackMagic Cinema Micro. Am very happy with it. Nothing wobbles and there is no play. The wide-angle kit lens fits perfectly and the vignetting is not noticeable (logical! APS-C sensor of the Sony is larger than the 16 mm sensor of the BlackMagic). Lenses with a fixed focal length of 35 and 50 mm fit just as well. The only thing I haven't tried is the 50-200 zoom lens, but only because I don't plan on filming with it. Overall I am very satisfied and can recommend it. Of course, it has no electrical connection to the lens, so you can't use LANC to control the focus. But that should be obvious anyway given the low price. For such tasks you use active MFT lenses or a booster, but I haven't seen any speed boosters for A-mount yet.

After having had good experiences with the Yonguo 50 mm, I also tried the 35 mm for my "second system" with the Canon M10. It's always a surprise how good these "cheap" lenses are. With an open aperture, the 35 has sufficient sharpness in the middle, which does not diminish at the edges either. The bokeh is nice and even. A little stopped down (F 2.5) it gets even sharper. The small minimum distance of 25 cm is pleasant. Of course you have to make compromises. The autofocus is loud and not as fast as a lens that is 5 to 10 times more expensive. On the other hand, it is quite reliable (not a problem on the M10) even in low light. The processing is good. It's plastic, but feels sturdy. And it's easy. In any case, it can remain as a fast normal focal length on APS-C.

Since I like to take pictures in poor light conditions (evening mood, technical photos, concert events) and otherwise like to do without the flash, I bought this 50 mm lens relatively quickly after the NEX-6 with the kit lens. I had previously found a number of sample photos and was pleased that the practical result lived up to the high expectations that previous reviews had given me. It's great fun to walk around the streets in the evening and to be able to shoot comfortably at 1/60 s handheld (ISO 800). The large aperture combined with image stabilization makes the almost impossible possible. A little leaning on a lantern or something similar and a steady hand have already made good pictures with 1/8 s possible. This is a great way to capture moods. The limitation here is of course the fixed focal length, which with 75 mm 35mm equivalent is a bit too long in normal living rooms to capture a party atmosphere, but is quite useful in the great outdoors/city or at concerts. Of course, portraits are also a fine thing. Due to the large opening, a very nice contrast to the background can be achieved. You have to be aware that the open aperture of 1.8 in the portrait distance can really only reproduce a very narrow range of sharpness, so it is not possible to take a pin-sharp picture of the head from the tip of the nose to the ears, but it has to be also not always be the full aperture. Anyone who likes to focus manually will notice a big difference to the 16-50 mm kit: the "translation" of the electronic, very wide focusing ring is many times larger than what is usual there. It can therefore be adjusted in a very differentiated manner, even in small areas. I am very happy about this purchase and can highly recommend the lens for the described area of application. If you are interested, there are practical "hobby" example pictures of my first attempts on the Internet at "Flickr", where you can find me under the name "bruderfranziskus". (Search on flickr -> try people)

Advantages: + Beautiful bokeh + Very high light intensity + High sharpness Disadvantages: - Slight color fringes at 1.4 aperture. (Optimal use 1.6 or 1.8) Application: - Portraits: I use the lens as a portrait lens on a 500D. The crop factor of 1.6 makes it the ideal 80mm portrait lens with a very nice cropping when the aperture is wide open. Due to the high light intensity, I can also take pictures in adverse light without any problems. The lens is also very well suited for outdoor shots of whole people, provided you are at a certain distance. I've had the lens for a month and haven't even looked at any of my zoom lenses since I'm so impressed with the image quality and speed. Alternatives: - Cheaper: Canon 1.8 50 mm (-worse image quality + much cheaper) - More expensive: Canon 1.2 50 mm (+ better image quality + slightly higher light intensity - completely different price range.) - Third-party manufacturer: Sigma 1.4 50 mm (+ slightly better image quality - should often have focus problems) - third-party manufacturer: Planar T* Zeiss 1.4 50 mm (-no autofocus +-image quality comparable +Zeiss)

The filter is huge.
7.4mm thick and 159gr weight, designed probably more for outdoor use.
Multi coated surface (28 layers), filter made of glass, scratch resistant, waterproof,....

You get a shock when you hold it in your hand for the first time.
There is a scale in the front that shows the approximate values, all of this is easy to grip on the frame itself or adjustable with the small handle that is screwed on.

The filter rotates completely, i.e. at the end / ND1000 comes a tiny step before it goes up again. Because there is no stopper, you have to be quite precise to get the highest ND value.
Even though it is of course the common design of these filters, I don't find this particularly practical or easy to adjust. You really have to pay attention, the scale doesn't really help there because the highest effect comes after the ""1000ND"" entry. And a little bit of rotation further, the ND decreases again.

Optically everything is ok, I could not notice any major / disturbing color changes - at least nothing that one would not have expected with this type of filter.
With and without the filter, the image remains sharp.

The whole thing comes in a plastic bag, where the filter sits loosely inside, without any further cover - again, I'm rather the friend of the closable plastic covers, but ok.

For 80 euros you get a good tool at hand.
For me, not the optimum, but that is complaining at a high level.

I use it mainly for video with my Canon M50 and the 50 mm 1.4 lens. The quality is great.

Anyone who likes to take pictures knows what you use an ND filter for. Since my focus is landscape photography I can't help but work with such filters. I ordered this one from K&F for my full frame camera.

I was tired of filling my backpack with ND filters of different strengths. The Nano-X was just what I needed. I ordered it in the size 52 mm. I then work with step up rings to be able to use it on smaller lenses.

To say it right away: The optical quality and the quality of the images has convinced me! The workmanship is excellent and very successful. The lens thread is top clean cut.
The filter is adjustable from ND 3 to ND 1000. The larger steps (f stops) are marked on the ring and easy to read. So you know what you have set.

The 52 mm. Filter brings 28 gr. on my kitchen scales. Everything is solid and feels very good. The setting runs well with slight resistance. This is how it should be.

The optical quality is absolutely flawless and even in difficult lighting conditions the filter delivers top. Chromatic aberration or color gradients into the green, magenta or anywhere else I have not been able to determine even when pixel peeping. Even with foliage or fir trees in backlight and with reflections from dew, the quality of the filter is unsurpassed. Finally a ND filter that does justice to my limited lenses and the full-frame sensor. The frame thickness with thread is only 10 mm. Without thread 0.75 mm. So I can use the filter on wider angle lenses without edge shading.

Thanks to the screwed handle and the ribbing of the ring, the filter can be adjusted very sensitively.

Conclusion:
K&F Concept has delivered a top filter. What's the use of spending thousands on lenses, but then bad filters make work difficult or lead to lousy results? From me clear 5 stars. I hope this is useful for your purchase decision. Also the price is relative since you save at least 4 ND filters.