All in all a filter that is worth the money and very manageable in terms of purchase....
I simply copied the complete text from my YouTube video for you. Who wants to see the video
"Variable Nano X Slim ND Filter I pure waste of money when buying?" Enter on YouTube...It's ND Filter that's hard to beat for value for money. It's about a filter from the company K&F Concept, this manufacturer's name is actually familiar to everyone who is - a bit - at home in the photo and film segment. And K&F Concept also stands for quality.
It's about the filter called NANO X Slim Filter. It is offered from a 37mm thread and goes up to a 86mm thread. Thus, it covers almost all offered lenses. He weighs just --- 45gr.
He has a total of 5 f-stops, it starts at ND2, 4, 8, 16 and ND32.
The filter comes with a nice round packaging as a transport box, so that it can also be safely stowed in a backpack or bag. But what is most important, especially for those who always leave the filter on the lens ---like me--- is the fact that glass is the filter's scratch resistant.
Screwing it on and off is wonderfully easy. If you buy it, you should definitely note that you can then usually no longer use your lens hood. Because the thread size on the front lens changes. Attention, however, when buying sun visors - it is essential to pay attention to the zoom range in which the lens is and accordingly buy a sun visor. Of course, I also had to buy a new sun visor, which I bought first was from 24mm, not intended for wide angle. My lens was 17mm – 28mm though. When I was completely in the zoon out, on 17mm, I had nice black edges in the picture. --- Stupid beginner mistake stop. So be sure to pay attention to the zoom area covered by the sun visor before you buy, just as a little tip.
The ND filter can be set very easily to the different ND levels and the individual levels are very well marked, so that you always know exactly which level you are at. Changing the ND levels is so easy because the filter is slightly corrugated all around and has a small pleasant resistance when turning.
In some recessions I've seen that some say the filters would appear to produce X-patterns at high f-stops. What I can't confirm with my film work at first. There is a spin stop, and no overlap, when setting ND16 to ND32, so the X doesn't actually show up. I only have the filter for filming, I'm a videographer, not a photographer, and I think it does a great job. A photographer and a full professional filmmaker will probably not use a variable ND filter anyway. I film a lot at f1.4, f2.0 and 2.8 and shutter 1/50 and even there, although everything is very open glare, the filter comes through perfectly, and very well with. Unfortunately, and that would actually be the only thing you could complain about, is that the filter has no IR cut. In plain language, --- IR, --- means infrared blocking filter. This blocking filter blocks wavelengths in the infrared range. What this filter does not have. But at the price?? somehow also understandable.
What does an ND filter actually do? ...
If some should ask themselves that.
Quickly and roughly explained ---- little basic knowledge.
First and foremost, an ND filter reduces the incidence of light and so you can still film in very bright situations, for example. Without totally overexposing the recordings. So also a longer eg. shutter speed possible. Who doesn't know the great pictures of streams or waterfalls, where the water looks like a veil, like in a dream world. You get that with a good ND filter and exposure time, for example, and not, as some people think or suspect, with good Photoshop skills.
I work a lot on the water, on the beach, on the sea, and that's how I always get the water nice and smooth.
