This K&F 2-in-1 filter is a clever idea for anyone who uses both a CPL and a mist filter while shooting. Instead of stacking two bits of glass, this gives you the glare control of a polariser with the gentler highlight bloom of a quarter strength mist filter. I tried it on a lens I normally use for outdoor portraits, and the mix of contrast control and subtle diffusion feels about right. The mist effect is not heavy, more of a soft lift around highlights, which is what I prefer when shooting in bright conditions.

The colour rendering stays neutral. I did not see that warm or green shift that some budget filters create. Reflections are noticeably reduced when you rotate the front ring and the coatings seems to keep stray light under control. It gives the image a slightly matte look in harsh sun, which helps when I am shooting in the middle of the day with limited shade. The CPL ring turns smoothly, not loose, and the overall build feels tidy for the price.

The filter adds a small amount of light loss, which is expected, but it is still usable for video without forcing settings too far. The thin profile keeps vignetting to a minimum on my lenses. The only small detail that stood out is that my lens cap does not grip quite as firmly on the filter threads, so it takes a bit of extra care when packing my camera bag.
For anyone who wants to keep their kit simple, this is a neat way to travel lighter without giving up creative control.

Pros:
Combines CPL and mist filter in one
Neutral colour rendering
Smooth rotation
Good flare control
Soft, natural diffusion effect

Cons:
Some lens caps may not grip tightly
Slight light loss when polarising

The K&F Concept True Color and Ultra Low Reflection CPL and Black Mist 1/4 Filter is a practical option for outdoor portraits and video. It's well made, and a practical and convenient combo filter, and adds a certain gentle cinematic look while keeping images clean.