I have the 1 and it looks amazing. The filter is well made, the thread is the same on both sides, so that ND filters fit well. it could be cheaper to buy, but it made my work a little more interesting.

As most K&F products, the build quality of this filter is quite nice. The threads are smooth, filter ring is powder coated and then optics... well, hard to say they're clear or anything since they're a diffusion/soft filter, but the picture quality is still quite good. More on that later.

The filter comes in a circular filter case that is one of the neatest filter cases I've seen! If they don't sell those as products yet, they honestly could! There are raised partial circles that allow you to place all sized filters in the case, unlike most with a foam cutout (which, admittedly offers more padding). It would be nice for the filter case to have a small sticker on it to indicate what is basically on the box--"NANO series 52mm MRC Black Diffusion 1/4" in my case. In fact the outer box has that listed a few different times, including twice on the sticker label... one on the case would be even better.

The optics look like a clear glass with a bunch of small grey dirt specks. That is the intended design. The effect it creates is a soft diffuse glow; a bloom effect. The contrast is lowered when using this black diffusion filter and overall it looks like a similar effect to a soft filter. The sharpness at the point of focus isn't too affected though, so it can still be used in portraiture as well as in other creative photography. Light sources will bloom when looking through this filter. I find the 1/4 strength to still be quite useful while the 1/2 an 1 may be more niche.

Shot a couple of cars and I love the finished product! I haven't had the pleasure of shooting portraits with it, but wow, I'm blown away.

Very subtle through the viewfinder, but there is a noticeable affect on exposure time. For achieving a vintage portrait look, this thing is fantastic, especially when coupled with a manual focus legacy lens - I have mine on a Rikenon 50mm. Sharpness is greatly reduces, but not in a "cheap lens" way, just a subtle and even softening. This brings to mind the famous Pentax "soft focus" portrait lenses of the 70s, but is a far less blurred image. Handy to have in the kit bag, but not really good for much other than portraiture. I have yet to try a K&F product that I am not absolutely impressed by.

It works well for creating a blur effect that is difficult to create in video post-production. I would also recommend the 1/4 or 1/2 power version as the effect is sometimes too strong.

Imho your quest for a mist filter ends here. I didn;t know I needed a mist filter until Itried this one from a friend and the same day ordered mine.
Super fast delivery too!

Bought it for my mirrorless camera. I love the effect that is out there, much like filters used in films like Minority Report and War of the Worlds by Steven Spielberg, it gives a softer, more diffuse, dream-like image. It's pretty strong, check out examples online to see how other strengths compare.

I love the look this filter gives my video, I can't live without it!

I am happy to have purchased this K&F Concept Filter Black Diffusion Filter 1/4 82mm the effect in the videos is very pleasant and cinematic.

Really nice quality filter, comparable to more expensive brands. Has that black pro mist look. Softens things and gives lights a bit of glow. The he 1/4 does enough but id be curious to play with the stronger versions too.