Top workmanship and very practically packaged

have two of these variable ND filters with 55mm and 67mm filter threads. The filters make an absolutely high-quality impression, which is also reflected in the packaging, especially the storage box. The filters have a scale on the aperture ring that starts at ND2 and ends at ND400. There are 8 stops in between. Unfortunately, the respective extension factor for each stop is not documented, so the exposure time is difficult to calculate. Here you have to try things out to get the best result.

If you want to see the parasol, it is also significant

A little expensive

Item arrived very timely ... the Packaging and Material Construction of the filter looks very impressive & excellent quality visually. I didn't have a chance to fully TESTED it yet, here's a quick SAMPLE photo of what it can do for shots in bright sunlight ... ! Looking forward to using it more in the coming Spring days..

purchased the K&F Concept Variable Neutral Density ND2-ND400 (9 stops) Variable ND Filter with Rotating Ring to be able to use a fast ND with different densities. The packaging is very well made, solid and compact container. The glass filter is light and the ring to increase/decrease the density is fluid. It does not have an end-of-travel lock. To test it at its best I tried it with three different lenses on a Nikon D750 camera (full frame): 20mm, 35mm and 85mm. - 20mm: in the photos taken with the filter there is no particular loss of sharpness, it introduces a slight warm dominant that is easily resolved in post-production. As for the X-shape problem, it is quite marked using the filter beyond the marked ring. Using it instead inside the marked marking the problem is not very present. See attached image. - 35mm: in the photos taken with the filter there is no particular loss of sharpness, it introduces a slight warm dominant that is easily resolved in post-production. As for the X-shape problem, it is not as marked as in the previous one, but there is a vignetting especially when used at maximum effect. See attached image. - 85mm: in the photos taken with the filter there is no particular loss of sharpness, it introduces a slight warm dominant that is easily resolved in post-production. As for the X-shape and vignetting problem, they are not significantly present. See attached image. Optically, therefore, the filter appears to be well made and provides excellent results, but I would have preferred a start and end stop with a lock in order to avoid possible errors. Also considering that K&F produces other types of filters but with a magnetic attachment, I think it could be an additional plus for this filter. The quality/price ratio is correct based on the performance provided. I attach additional photos of the packaging and two shots at the seaside.

K&F Concept is synonymous with quality. I already had other filters of theirs, even though they were quite old and with several years of service behind them. In light of an upcoming photographic trip of mine, I decided to opt for something new, always relying on them. I will tell you in detail what, in my opinion, are the pros and cons of this new product of theirs. First of all, the packaging is really excellent: the box is made of very sturdy cardboard, impossible to fold, and the magnetic opening is very pleasant. The filter is stored in a leatherette case with a magnetic closure and not in plastic, which gives the product a finish that we can define as "premium". Inside, wrapped in a protective bag, the filter. It is a fairly heavy piece, but it already gives an excellent impression to the touch. The body is made of aluminum, the glasses are of excellent finish. Very thin (and this is a good thing because this reduces any loss of sharpness), waterproof and scratch-proof. Very nice (and very useful!) the orange thing that is used to vary the intensity of the filter itself: the only flaw is that it does not have a limited stroke during rotation, but it is not a big problem, since the ND2 and ND400 limits are indicated right on the end of the filter itself. In any case, the filter has been built in such a way that, even when exceeding the limits, the annoying "X" shadow does not appear. For the moment I have only had the opportunity to try it in the city on a somewhat gloomy day, in the next few days I hope to integrate this review of mine with other shots in the mountains. Who is the filter aimed at? Certainly those who love landscape photography or those who want to take long exposures in the city (staying within the limits of 9 stops): of course, the product is not the cheapest on the market, but you just have to try it for a while to understand that it is worth every cent spent. I am not a photography professional, but for my use it is more than enough.

This is a great filter, Have several k&f filters and the quality is fantastic, Overall a recommend buy

very surprised by the quality of the filter, it's professional, nothing to say. The materials are good and the glass is superb. The adjustment wheel is very fluid and allows you to easily change the density of the filter. no need to have 4 different filters. possibility of shooting video in broad daylight at the widest aperture. I love it! it also comes with its small carrying case which is very solid and allows you to transport it easily without fear of scratching it

was afraid that it would have problems because it is a variable ND with strange effects, and there were no problems. Neither in the corners, nor at ND400, the truth is that it was a pleasant surprise for its price. It may have a bit of a green tint, but with a minor correction in Premiere I have solved it, between 5 and 10 points on the tint tab towards magenta and that's it. Highly recommended, it only needs to have a stop like the ND2 and ND32 models that are the ones I usually use.