"Die-hard" photographers know that you need ND filters for long-exposure shots. I somewhat "misappropriated" this filter because I didn't want to take long-exposure shots, but rather film footage. For this purpose, I screwed it onto my film camera (Canon EOS R5 C with 24-105mm / F4) because we were driving through very diverse (exposure-) landscapes with the camera – and the manually shot film footage constantly required adjustments. Upon later review, these shots were flawless – and a much more expensive professional camera couldn't have produced a better 8K image. I will also use it for long-exposure shots.... Thumbs up

Very good but returned because I didn't like having to stick a filter holder on to put it in

Worked as expected

I’ve never used a variable ND filter, so this was really cool to be able to test out. It came in a protective plastic hard case along with three microfiber cleaning cloths. While slightly heavier than normal nano filters, I still was surprised at how lightweight it was comparatively.
Adjusting the strength of the ND was smooth as butter. The ring glides with minimal effort to achieve a lighter or darker filter between the min and max settings. If you keep twisting it past these points, it goes through the same grading scale until it reaches the starting point again. The threading is well made, so installing it on my lens was easy.
After some testing, I haven’t seen any vignetting or loss in sharpness. There is only minimal color shifting, and I didn’t notice any until around the ND1000 mark.
The image quality is fantastic with this, but the really beauty of it is the convenience. While it doesn’t take a long time to change a filter, it becomes annoying quick having to switch multiple times. It also takes up precious space in your kit when you are trying to travel light. With this, there is no more fumbling with multiple filters trying to get the right combo for the shot. If I need to adjust, I just give the ring a quick twist and I’m good to go. And instead of a case with multiple filters taking up space, I have one filter that does the job of a whole set. It’s absolutely fantastic. Nice job K&F!

This variable ND filter by K&F Concept is really well made. The threads and fit are perfect and the optical quality is better than I would expect at this price point. I like the convenience that a variable ND filter provides and this one has enough of a range to meet all of my needs. There are no hard stops on the setting, but the rings are stiff enough to stay where I set it and I don't have to worry about accidentally changing the setting if I bump it. As with other K&F Concept products, the included individually packaged cleaning cloths are also a nice addition. Overall, I'm very happy with this filter.

This filter is great. I've used static filters quite a bit but haven't used variables much. I love the motion of this one it glides very nicely. It has a great result and is well made. It doesn't add much weight to my camera either. And the carrying case is a nice addition since I don't leave it on my camera all of the time. Its a nice product and would definitely buy again.

As long as you know you won't likely be able to use the full range, this is a good deal (see video). The "X" pattern is almost certainly a sure thing with this kind of range. Still, the price is right.