77mm Ultra-Low Reflection Variable ND Lens Filter, ND2-400 (1-9 Stop) HD Adjustable Neutral Density Filter with 28 Multi-Layer Coatings for Camera Lenses - Nano-X Series

Another excellent filter from K&F , from the packaging to the filter itself. Packed in a secure box then inside a leather look magnetic carry case. The filter itself has very well made glass with a metal grip for adjusting the ND range.
Fits onto my camera securely and the ND turns not too easy which is what you want really. Not the cheapest but deffo a lot of work has gone into the manufacture of it.

I shoot a lot of video, so decided to order a new ND filter for a new lens I recently purchased that has a 55mm filter thread. I thought this one offered a pretty good value for the money, so thought I would give this a try. So far, I find the image clarity more than acceptable, and with it being a variable filter, it functions great and can be used in all sorts of different lighting situations. The threads are machined nicely and I have no issues with installing or removing the filter from the lens, making removal very easy. I do not have any issues with vignetting, and thing that the color shift is acceptable. I plan on getting a lot of use out of this filter.

Good budget variable ND Filter

Includes a thin leatherette container with an interesting pull strip to help eject the VND from the case. It has a slightly magnetized front seal that will prevent it from accidentally opening.

The VND is well-made of metal with a smooth beveled edge for easy gripping. There's an easy-to-see to see bright orange lever which has an extremely smooth travel. Going 9 stops gives you very broad coverage in even the brightest sun. This is a major convenience compared to 5-stop filters that require changing or adding ND in brighter situations. I didn't see any X effect, but there are no stops at the start or end of the range, so it turns through the entire filter. One has to look at the edge of the filter to see the demarcation dots if you need repeatability. There's just the slightest color shift. These are the only minor issues, but given the value and 9-stop range, they aren't significant problems for me.

I chose 67mm because that works with both my iPhone clip and several mirrorless camera lenses I have with that sized filter thread.

Love everything about this VND! The fact that it covers 1-9 stops is huge, as most filters usually cover 1-5 or some other smaller range which makes it necessary to carry additional filters. With this one, it not only covers a wider range but it doesn't shift the colors too badly to where you end up spending a ton of time in post processing to correct it. So far I haven't had any weird X-patterns either, though I've only used it on 67mm lenses. With that said, K&F did a great job with this one!

This variable nd is a great deal. The quality is right up there with big names (likely uses the same glass) and it doesn’t seem to have any noticeable color cast. It turns smoothly but isn’t loose and it fits threads like it is supposed to. I like the little tab for turning it, it’s a nice touch that also makes it faster to visually check where you have it set to. It’s all metal and feels solid. Overall it just works like it should and gives you flexibility and control over ambient light.

Amazing quality again from K&F. The image quality is wonderful. It is durable and functions as needed. The color accuracy seems to be really good. My only complaint is that there are no hard stops on the variability. Other than that, this is a great filter that covers everything you need in one lens.

I have some fairly expensive and capable ND filters already, but they are like candy...once you start, it's difficult to quit them.
I like K&F products and have owned many over the years. This filter is a great addition from them. 9 stops is nice, I stay away from the filters that try to do too much. Physics can be annoying at times but it can never be ignored. Something usually ends up on the weak side.
But with 9 stops, they get it all done proper. I have included a 10 second video where the aperture and the shutter speed is a constant. I am changing the exposure by only moving the ND from 1 stops to 9 stops. Auto ISO to compensate as well. As you can see there is very little color shifting going on. It probably will not ever show up in typical field work videos. Everything shifted with buttery goodness, nice and smooth.
That's the forte with this filter...video work. It can do stills of course, but the filter is really setup for video. No more 'click click' when I hit the end of the stops. It happens more ties than I care to recall. Not with this filter, there are no hard stops...the rotation wheel keeps rotating buttery smooth as the lens goes darker and lighter. Once you get to know the filter and how it acts on your favorite video lenses...the design will really help the work along.

Fit and finish is top notch and they have included a nice leather case for it. I have a top end filter that costs 2.5 times as this one (some out there are even more), and it has a touch less of a color shift. I do mean just a touch. At the time of that expensive purchase, if I could see the two side by side...I'd buy this K&F and be done with it.
This K&F filter is just as sharp as my top tier filter as well. It does its job and gets out of the way...wonderful.

Very nicely done...recommended.

Very nicely made Kase screw in Variable ND filter. It turns easily and darkens/ lightens smoothly as you turn. It is metal and feels like a quality product. It screws on smoothly and easily. Perfect for bright areas where you want shallow depth and a wider aperture, or slower shutter speeds to capture movement. Comes with a handy and protective case. It is not too thick and shouldn't cause vignetting unless used on a pretty wide lens. I am using it on a 50mm lens. Not inexpensive but a good value for the quality of the filter.

It's very close to perfect, I just wish that they would put a stopper when it reaches the limits... Instead it keeps turning round and round. It's not a big deal but it would make life easier if you did not need to look at the settings and just do it on the fly by the feel.

K&F filters have come a long way. This filter is sharp and has no aberrations around the edges. If you need a good ND filter for not a lot of money, this should be on your list.