I've had and still have many K&F products, so I'm not surprised when it's this good. It always is. The packaging. The carrying case. Both look like they hold fine jewelry. Sharp-looking, with sturdy construction, and the result is absolutely amazing. Cuts down on all the harsh glare/reflection, and smoothes everything over. And so much better, being variable, than having to try multiple filters to get the desired effect. Love just being able to adjust it to where I want it. And, it works like magic. Thank you, K&F Concept

The built quality is amazing. I used it with several lenses using a step-down ring and it worked flawlessly with no issues whatsoever. I haven't noticed any weird colors in my pictures.

I use this on a set of Meike S35 lenses with a Black Magic Pocket Cinema Camera 6K - very pleased with the ability to change the picture results to be a little softer and dreamier - all while keeping weight down on a gimbal.

As a hobbyist photographer, this is admittedly an aspect I haven’t tried out yet, so there was a bit of a learning curve with getting to know how to use this filter. The fact that the adjustment is smooth and has no direct stops is probably good for someone more familiar with using these, but was a bit tricky for a new person. However, I love the effects you can get with this filter without taking up much space. It’s really nicely built so I’m not as worried about breaking it by accident, and the carrying case slips easily into a camera bag. All in all, getting to know how to use this filter has been a pleasant experience and I find it very worth it.

K&F Concept black diffusion Mist ¼ effect & Variable ND2-400 is the first combination filter I am trying out. At first look, the filter comes in a very nice retail box. Inside the filter is package in another soft storage case. There is a strap that when you pull it will push up the lens out from the storage case. The lens feels solid with a orange turning knob that allows easy turning of the lens. On one lens you can small faint black dots at an angle. I think that give the mist effect on the photo? Overall, I am surprised the lens is made in China. Most of my early filter lens is from Germany or Japan.
The dreaming effect of the lens is interesting. I am learning how to use it. It gives a softer effect but also diffuses the background sun light in an exaggerated effect which often would overtake the subject. The ND filter is good to increase the exposure time. But the filter does not have a hard stop to tell you how much light is restricted. It is great for video since it is stepless, for still photo you will need to play with the setting.
I am new to this combination filter and using it on Nikkor 24-70mm f2.8. At the end of the testing the ND filter, it accidently locked onto my UV filter. I am waiting on the lens wrench to unscrew the filters apart.

I recently got the K&F Concept 67mm Black Diffusion Mist 1 4 Effect & Variable ND2-400 (1-9 Stops) ND Lens Filter and it is incredible! This filter has adjustable levels of density, allowing me to get the exact effect I'm looking for. Not only that, but it's multi-coated with 28 layers of Nano-X Series and made with high-grade materials that feel sturdy.

price and quality are in line because you definitely get what you pay for so this is a great addition to my camera.

You will not find a single negative thing to say about these.
Perfection as usual from k and f

I can hold this easily with one hand and my camera in the other. It does have an insert where it looks like you can mount it to a tripod at the handle but none of mine fit. It’s a pretty big insert. If I can find that size that would be perfect to attach this too.

First time using an ND filter let alone a 2-in-1 filter, very easy to use, much cheaper than other brands, so far so good