With no visible X or color cast, I'd say this is a good VND filter.

This CPL ND filter is awesome. The build quality on this filter is immaculate. The threading is all metal and just glides. Theres no annoying X pattern on the ND side of things and it does an excellent job at getting rid of unwanted reflections as well. The optics are also excellent there is no dip in quality and the coatings really help to cut out glare and purple fringing.

I’ve been a fan of K&F Filters and accessories for some time now, and have come to appreciate the consistency and the quality of the brand. The majority of my lenses live their lives with K&F UV protective filters on their front element.

Like many others, as the caliber of mobile phone imagery and videography have improved to levels of near professional quality, I’ve begun to concentrate more energy into taking advantage of those attributes, not to mention the portability. Both in videography and photography, whether using a full-size camera or a high-end mobile phone, I consider both ND and CPL filters essential.

In hand, the K&F Concepts combination Variable ND2-32 and CPL filter gives the impression of quality. Between its matt black finish, the gold adjusting levers and the reflection of the multi-coatings, it’s also an impressive filter. In fact, I own a couple K&F variable ND filters in other sizes, although this is the only one that includes the CPL.

A variable ND filter works in a similar manner to a CPL, that is, there are two-rings, one that attaches it to a lens and the other that is turned to control the degree of transmission from more or less light, effectively allowing control of exposure. In this case, it’s the CPL that attaches to the front of the lens, with the ND component in front of that. In order to control each independently, the CPL has more resistance when being adjusted than does the variable ND component, which is adjusted using the gold levers on the side of the filter. That being the case, the user first adjusts the CPL to the desired position, then adjusts the variable ND to facilitate the desired exposure; it’s a system that is thoughtfully designed.

A ND filter, whether variable or not, is used to reduce the amount of light reaching a light sensitive material. In videography, it is generally used in order to follow the convention of a low ISO and a low shutter speed or a specific shutter angle. In still photography, it's used to allow for the use of a wider aperture in bright light situations or to reduce shutter speed for some desired effect. In either case, the benefit of the K&F Variable ND filter component is that the transitions between minimum and maximum light reduction are not stepped, but infinitely variable between its 2 - 5 stop range. In other words, one can set their camera to the desired settings, then rotate the light reducing transition ring to achieve the desired matching exposure.

A CPL Filter is used to reduce or eliminate certain non-specular reflections and also to saturate colors, for example a blue sky. Generally, a CPL itself requires a certain amount of exposure compensation, in my experience somewhere between 1.5 – 2.0 stops, because they also add neutral density when placed in front of a lens. Interestingly, and baffling, is that K&F has compensated for the ND effect of the CPL in their calculation of the variable ND component of the filter; when the ND is adjusted to its minimum variance, that is ND 2 (or .3), only one stop of exposure is reduced, not one stop plus the exposure reducing effect of the CPL.

Testing the filter for any reduction in image sharpness not only revealed none, but the example with the filter in front of the lens actually looks a hair sharper to my eye; each image has been enlarged to 505%.

The K&F Concept Variable ND plus CPL Filter comes from a trusted manufacturer, is high quality in fabrication, light transmission, and materials, and is essentially two filters commonly used together in one efficacious assembly. In other words, this single assembly allows for some control over distracting reflections, can enhance color saturation and allows for precise control of exposure settings, in what can otherwise be uncontrollable circumstances.

The K&F Concepts Variable ND plus CPL Filter is delivered with a hard plastic case and a nice cleaning cloth.

I have had a few K&F filters over the years...and I have found it to be hit and miss...but there are a lot of variables involved and I still go back to them.
This one is a hit.
I have included two images...involving some greens and blues...one is maximum ND and one is minimum ND...only the shutter speed was adjusted for exposure...and both images look natural and clean...good details in the pines.
I like the build quality, it has a nice heft to it.

So...why not 5 stars then? Just one niggle. I appreciate the adjustment grip on the sides...both sides...nice. But I think it needs to be dampened a bit more...just seems to slide too easily, and with the two grips protruding (you can take them off)...the filter could be moved without my even being aware.
It's a small niggle...I will live with happily...not a big deal...just not perfect...few things are.

Nice bit of kit...big thumbs up!!

I'm just an amateur photographer, but I really like this filter. It's like having two filters in one. The adjustable ND filter means that I don't have to keep switching out filters when taking photos. The filter is well made and works smoothly. It comes with a sturdy plastic case to keep the filter in when not in use.

I only started using filters about a year and a half ago, so my experience is limited. However for me, I believe this to be a quality filter. I did have to use a step down ring to attach to the lens I was using. To use this filter, the ND portion is adjusted with the tiny knobs and there are markings on the filter ring to guide you. The Polarizing filter is adjusted by moving the ring closest to your lens in a circular manner.

Here’s what I liked about the filter:
1. The housing is a metal housing and the moving parts glide easily. The filter is built well.
2. It comes with it’s own storage case which has a foam cutout to perfectly protect the filter.
3. The glass appears to me to be good quality.
4. I did not notice any vignetting when using.
5. Image sharpness was not significantly degraded.

The filter also came with a sealed microfiber cleaning cloth.

I like that you are basically getting two filters in one purchase and the filter is a good value. Five stars.

The lens filter has helped my son's picture quality. He is an avid bird photographer. He uses the 67mm lens filter on his Canon RF 100-400 F5.66-8 IS USM lense.

He enjoys being able to adjust the ND and CPL. Glad we got the filters and our son is extremely happy.

I’m really impressed with these filters. There’s a variable ND plus CPL filter and it works great. There’s no weird color cast or anything like that. The image is super clean. Also, I like the design with the two bolts that don’t allow the filter to over-rotate creating the dreaded “X” pattern that some variable NDs get. Also, it makes it so easy to know when you’re at the lowest setting and the highest setting. But most importantly, I just really like the image quality coming from these filters. Highly recommended.

I'm positive I picked the proper size filter but it came with a smaller one. Since I only have one lens that I can adapt it to I won't be able to use it with the lenses I had intended to use it with. I like the concept of the combined ND and CPL Filter I know I can stack filters to get the same result. But it would have been nice to have the two things in just one lens filter. The polarized lens It's very often handy to have for longer exposures Regardless that It's not the size I wanted you should be happy with the results you could get from this combination. I have always been happy with K&F filters

I picked this up to use with my Sony A6400 with Sigma 30mm 1.4. This is my go-to set-up for taking pictures of the family/kids but wanted this filter to be able to shoot wide-ish open during the middle of the day. So, basically it does exactly what it's supposed to do; there wasn't any noticeable distortion, softening or color changes, and it was able to drop my shutter speed enough to not blow out the highlights. What I really like is the knobs that allow you to change the ND intensity quickly - this is an absolute life-saver for shooting toddlers and young kids, as they are the fastest things on the planet and they're not going to wait for you to change the filter on your camera. The only negative is the need to potentially get a new lens cap as the filter diameter is larger than the lens cap diameter. This is addressed in the description, but it's just something to keep in mind. Overall though, it's a nice filter.