As with all K&F filters that I own, this one is well built and the machining is excellent. I have other black diffusion filters and I really like the look. This filter combines the black diffusion with an ND filter (all in one), and the ND is adjustable. The filter is a screw on filter and the threading is good. The filter also adjusts easily, but is not a lock stop filter. Adjusting the filter is very smooth and easy.

I didn’t notice any issues with vignetting and I didn’t see any X patterning. However, you do get a warm color cast when using. I included some footage which really shows the cast and I did not alter any settings in the camera so you will see just the effect of the filter at ND2. I should mention that I was away from the sun in the video. It is not as apparent for me when directed at the light source. When directed at a light source or sources, you do get a beautiful light spreading halo effect at the light sources.

In some instances I like the warm color cast. It gives a glowing homey feel for me. However, there are some instances that I feel like the warm cast is too much. It can be toned down in post, but that’s an extra step.

For me, this filter is a specialty filter. I like the look for certain situations. I would say if you want a dreamy, warm feeling in one filter that softens light sources, it is a good filter. The price point is good for the quality of filter. However, if choosing again, I would get two filters (one standalone black diffusion and a standalone variable ND) and put them together for hopefully the same effect as this filter, but giving more options to using separately.