So far from my limited testing it is a very nice filter. I have the 1/8 mist and it seems to just add a touch of softness. It also doesn't appear to introduce any strange colour casts to the image. The operation is also pleasant and smooth.

I got this in size 67mm to use on Ip15 Pm with a magsafe filter adapter. First time using mist filter, 1/4 is noticeable in video, taking the edge of iphone footage, soften the lights to get that cinematic look. The VND works as expected without noticeable vignette or X spot, together with Blackmagic camera app to achieve lower shutter for a natural motion blur. For non-professional eyes/content, this has great value for $.

I have two K&F Concept variable ND filters (NANO-K series ND 2-400, 77mm and 72mm), and both of them have obvious color shift effects.  So, I believe that the K series is at low end of K&F Concept ND filter.   However, a K series True Color variable ND (2-400, 77mm) is good, without noticeable color shift.
What about this K series Black Diffusion 1/4 & variable ND 2-32?  My guess is that it would work similarly with the true color type of K series.  And I am right about that.  I do a LED reflection test for all filters.  The K series ND filters have the blue color, while the true color one has the green color, similar with the true color ND filters of other brands.  This black diffusion/ND combination also has the green color, of some different degree. 
I like the softer effect of this new filter, and it appears to be an upgrade from the true color version of the K series, with added hard stop ends. 

1/8 ND filter. this is the lightest option for these type of filters, the effect might be hard to notice if you don't know what to look for. i adds a slight soft layer to photos/video, and especially at night or for light sources, it can add some flaring. do a google search for side by side photo comparison if you are uncertain.

Great filters! Took quite a while to get to me, but they fit well and feel really good. Threads are smooth and the black diffusion adds a nice mist effect against bright light. Makes it feel silky and ethereal in a sense. This is my first black diffusion filter, so I am still new to the effect, but its a cool stylized effect. The ND filter works great as well, though only going up to 32 is kinda weak. Which it went much higher to be more versatile, but it is what it is. Overall, good value for the money and if anything does protect the lens too from accidental damage.

This filter is absolutely perfect for still and video portraiture. The lens adds a nice soften glow to images that provides an almost ethereal look. The filter doesn't have any vignetting and when using the variable ND filter the image appears consistently darkened and doesn't have any cross hatches or "X" across the frame as I've seen on some lower quality ND Filters.

The filter is incredibly functional and I think that it is a fantastic value for the money and I would highly recommend tossing it into your camera kit for portraits and wedding photos to soften images just a tad.

This 72mm black diffusion mist and the variable ND2-32 filter is a solid addition to my camera gear. The combination of a diffusion mist effect and variable ND makes it incredibly versatile for both photography and videography. The mist effect is subtle but effective, adding a soft cinematic glow to highlights without making images look overly hazy. The variable ND adjustment is smooth and provides good control over exposure, making it useful for shooting in various lighting conditions.

The build quality is impressive, with a durable metal frame and high-quality glass featuring 18 multi-layer coatings. These coatings help reduce glare and reflections, resulting in cleaner images even in bright environments. The filter threads on easily and stays secure without any issues. I also appreciate the compact design, which allows for easy storage and quick adjustments while shooting.

One minor drawback is the slight color shift when using the ND filter at higher stops. While it’s not extreme, it does require a bit of post-processing to correct, especially in video work. Additionally, at the darkest setting, there is some minor vignetting on wider focal lengths, which may be a concern for certain shots. However, these issues are relatively minor considering the convenience of having both diffusion and ND in one filter.

Overall, this is a fantastic multi-purpose filter for filmmakers and photographers looking to add a cinematic touch while maintaining exposure control. While it’s not perfect, it delivers great value for the price and is a useful tool for creative shooting.

I love multipurpose filters like this. Cuts down on the amount of gear I travel with. Build quality is fantastic and I especially love the results I've been getting so far. Looking forward to testing some more.

I love this filter! It really is great quality, and makes shooting in different conditions so much easier. I would highly recommend this product!

images look great through this filter!