I really like the soft light that it produce in videos. It's especially noticeable in "color lights". Made everything more dreamy and cinematic, especially at night.

Great filter with nice features at a decent price. About 3mm thick. Screws on fine. Hard case.

In the pictures, the first image is with the filter on, the second one is without the filter. Shot with the Nikon 50mm f/1.4 lens at f/1.8. The main difference is in the highlights area. Note how there is loss of contrast and a gentle glow effect around the candle lights and around the stronger highlights. Also, there is a very subtle, dream-like haze in the image, the image sort of feels a little bit warmer.

I can definitely see how this filter will have its place in my camera bag.

Quality-wise, the filter is very nicely made. The storage case is hugely oversized. Looks like the same case size is used for all filter sizes. This is suboptimal for the consumer, since there is no reason why I need to find space for the huge case for a small filter.

The retail box is presentable, and projects quality. The whole package would make a nice gift.

I am usually against UV/haze filters as I am concerned about their effect on image quality. However, I plan to use my Sigma 150-600 DG DN Sport (Sony E-Mount) in pretty harsh conditions such as coastal bird photography, surf photography, and sports. So, I caved and purchased this filter to provide protection for the lens front element.
However, given that this K&F filter would probably be considered "mid-tier" in terms of price, I wanted to test if it in fact had any effect on image quality. The attached image of a $20 dollar bill was taken under the same exact circumstances - 600mm at ISO 100, tripod with OS off. As you can see from the screenshot taken in the compare view of my photo editing software, the image on the right (with filter) is clearly sharper with better contrast.
I'm shocked! I had fully expected to remove the filter when I wanted a better image. Now I can leave it on 100% of the time, and easily wipe off any splashes or dust without worrying about scratching the front element. Strong recommend!

Includes: case, and filter.
Tested with my nikon kit lens. (see my sample photos)
Each Top photo was taken on a tripod with a 10 second timer.
Each Bottom photo, the black mist pro filter was added.
This really does work as the name suggests!
Side by side you can see the colors and focus in the original without filter.
Then after applying the filter to the front of the lens,
you get a black mist. This calms down the color saturation and the sharpness.
Just a small amount.

The case.
Top twists off from the bottom and is made of a smoked plastic. The edges have a nice groove set.
Makes opening and closing easy. Branding on top.
The bottom is made of the same plastic and has the same grooves on the side.
The highlight is the 2 gray silicone pads that are glued down inside.
(These grooves will hold you filter) You could also use with smaller and larger filters.
That's a plus.

The filter.
Is slim line and made of aluminum.
Sides have really nice grooves, makes using the filter very smooth.
Great glass. Actually scratch resistant.
Took out my keys and hey no scratches. Thumbs up.
Waterproof.
Filter weighs only .5 ounces. Both the case and filter weight 2.7 ounces.

Overall very pleased with the filter.
Great quality.
I picked up the 52mm version.
Used 2 of my kit lens and no issues. Very smooth to install and remove from lens.
Easy to clean. Should last a very long time.

I prefer to shoot with filters verse going into software and spending extra time to get a similar effect.
Hope this was helpful.

Finally a filter that gives softness to my images without neglecting the details. It also corrects small imperfections on close-ups without detracting from image quality.

Very good!

I use this for street photography, portraits and car photography, great dream-like effects and any glaring light turns into a soft glow.

Amazing filter for night street photography in nicely lit situations. Street signs, lights, etc. Add a very nice soft glow to your images. During the day, it's add a soft cinematic touch.

Not on my lens 100% of the time but a very nice filter to have in your bag.

Was a perfect fit for my Nikon Z50! A must have for any camera to protect your lens and make it easier to clean. Found the price very competitive compared to similar filters.