It's my first ND filter and I was totally satisfied. Darkens the scene by 10 levels of light, allowing you to capture long exposure photos in full daylight in complete comfort. It's made of glass and looks good quality. I've used it with my Sony A6000 and haven't observed any dominant or aberration too appreciable. Comes with a leather case lined inside with a soft velvet fabric that is delivered very well so you can carry it without fear of scratches.

Good ND Filter for the 18-135mm Sony E-Mount Lens

I'm not ready to purchase an expensive 10 stop ND 100mm filter system yet. So I want to try this one out. The picture quality is solid for the money. Pic 1 (no filter), Pic 2(this product), Pic 3(K&F 40-1, 10 stop ND). Obviously, this is a big step up from plastic one (pic 3). In pic4, the pin holding the filter holder hinge was so loose. If you lose the pin, the filter holder become useless. The pin fell off when I first open the box. I didn't realize that until I tried to put the filter holder on my z6. Therefore, I decided to blue tape it to prevent the pin from falling out. I think it is a good buy if you are a amateur photographer.

This is tough to beat. Not only do you get a 100mm GLASS (not plastic) 10-stop ND filter, but you also get the filter METAL mount and multiple METAL lens adapters. Even if you need to buy step-up/down adapters because the ones included do not fit your lenses, this is still a bargain. Even though this comes in at well below the price of other 100mm 10-stop filters (without the mounting system), it performs excellently.

My unit doesn't produce any noticeable color cast, but I also shoot solely in RAW, so a color cast wouldn't be an issue anyway. The case for the filter is firm, so I don't worry about it very much when it's in my camera back, and the soft lining keeps the filter safe from scratches (so long as nothing coarse gets inside, of course). Better still, the filter mount features a second slot should you wish to use additional 100mm filters (e.g. graduated filters). I point out the size because this is the "standard" in these filters, rather than the more common 80-something mm ones you see in comparably-priced square ND filter bundles that use smaller, cheaper plastic filters instead.

The only issue I found, and this is really just nitpicking at this point, is that the filter mount never really feels very securely attached to the lens. The filter and mount won't fall off if the camera is moved or tilted forward, but the mechanism that attaches the mount to the lens adapter could be a bit tighter fitting in my opinion. Nevertheless, great product at a great price. Anything "better" will be considerably more expensive, and even then, how much "better" will it be?

In use on the Sony 20mm F1.8G and does exactly what it's supposed to do. Use it for videos in the sun

Rating: 5.0 from 5.0

Quality of workmanship: ⭐️⭐️⭐️ ⭐️
Variable: ⭐️⭐️⭐️ ⭐️
Suitability for practical use: ⭐️⭐️⭐️ ⭐️
Material texture: ⭐️⭐️⭐️ ⭐️
Price: ⭐️ ⭐️ ⭐️ ⭐️

I was allowed to test the variable ND filter (gray filter) ND3-ND1000 of the brand K&F Concept.
For me it was the first contact with a variable filter.
Accordingly, I was over the large width of the setting of 1.5 - 10 f-stops by just moving the hand lever.
As an amateur photographer, I use a variety of filters up front that I carry with me on occasions like our vacations. It may not be the same for others, but I always sweat blood when changing screw-on filters in the middle of the field, scrupulously careful not to paw at them with my fingers. As of now, the camera case is a bit lighter and it stays with a single filter. I like that already very much.
But the filter was also already delivered in a valuable box, in which there is a noble bag as storage for the filter. I guess every hobby photographer is very happy about such a noble gift. But before buying, you need to know the diameter of the lens thread you are using. In my case, I ordered the filter for my normal lens that requires a 58 thread size. On the other two lenses, 63 filters would then be used.
In testing, I was thrilled with how easy it was to adjust and the quality of performance and workmanship is exemplary. Only, it would be nice if the setting had a min-max limit. So I had to always once briefly direct an eye on the lever, whether it is also in the adjustable range.
But this is complaining at a very high level. In any case, I am happy about this great filter and that the eternal change finally has an end.

Conclusion:
Very well made, variably adjustable ND filter (aperture 1.5 -10). Recommendation!

I hope that I could be of some help to you with my review. Thank you!

This filter can compete against the biggest brands in the business. It has exceptional optical clarity and is a true 10 stop ND filter. I use this filter for long exposure shots, particularly nature shots with running water. However, there are many uses.

The overall build feels like quality throughout. This series from K&F knocks it out of the park and is a bargain for the level of quality. Easy to recommend.

It is a variable and polarizing ND filter. The ND is 5 steps, there are double, 10 steps (ND1000, 1024 to be exact). The polarizing filter eliminates light reflections on surfaces, cars, water, glass and also enhances the colors of the sky, leaves, asphalt, etc ... (search the internet for more information) Personally, I use it for videos so as not to by closing the shutter to lose depth of field (f9 up, now I can go to f2.3 without burning the frames due to too much light). I haven't removed it from my 35mm in a long time, I'm thrilled.