Never understood the point of ND filters until I got one. Actually great for indoor use as well! Softens any harsh light!

Super qualität, vielen Dank.👍❤️

Most of the Square style ND filters are so expensive, but K&F's new line are very affordable. The glass quality is just as good as those that costs a few hundred dollars. It comes with a storage pouch, which feels very high quality, and provides very good protection when storing it in the bag. I am totally loving it, and would get it again.

I'm gradually getting into matte boxes and square filters such as this. I've had great experience with K&F's circular filters that thread onto the front of my lens, and this square filter by them meets my continued expectation of excellent quality from K&F. It fits well, albeit tightly, in my Neewer matte box, though I believe this is more on Neewer's side than K&F's side. The 3-stop ND filter works great. I don't notice any significant color change. Obviously, there's no X issue as it isn't a variable. I love it. Carrying a square filter around is much more cumbersome than a round filter, but it's a learning experience.

This is a perfect fit for my smallrig matte box and I was incredibly impressed with the quality of the packaging. The filter comes in its own, faux leather case with magnetic closure. When opening the case it pulls up on a ribbon that goes under the filter making it so that it pulls the filter up high enough to get your fingers on the edges without needing to touch the surface of the glass. I have checked it for a color cast yet, so I can't speak to that, but so far I'm very pleased with it.

At about 4mm thick, with its measurements of 4” x 5.65”, the K&F Concept 0.9 ND Cinema Filter is a pretty hefty chunk of glass, and with all those coatings, on both sides, a beautiful thing to behold. A 0.9 ND filter is used to reduce transmitted light by 3-stops, allowing the user more options and better control of exposure in brightly lit environments.I have a number of K&F Concept filters, most of my lenses live their lives with a K&F protective filter on their front element, and I own some of their other photo/video accessories as well; I consider them a trusted manufacturer.As the seller asserts, their Cinema Filter is sized specifically for Tilta and Smallrig mini matt boxes, although there may be other manufacturer’s matt boxes that they fit. A matt box fits onto the front of a lens, basically serving two purposes, as a filter holder and a lens shade. In the case of the Tilta matt box, there are grooves on the leading edge into which the filter slides and is held snuggly in place.Handling the filter takes some care, since it is not enclosed in anything, for example a frame, but is glass from edge to edge. In our case, we keep cotton gloves around for such situations, and use them when handling the filter. Oddly, K&F Concept has always provided a cleaning cloth with every other filter I’ve acquired from them, but not in this case; it would be nice if they did, but I’m not complaining.The filter arrives in retail packaging, with a magnetic closure, that is a storage case unto itself, however the actual filter case, that gives the impression of faux leather, is exceptional. It has a flip open flap (a flipping-flap) with a bright orange nylon strap attached that when pulled, slides the filter up and out, making it convenient to grasp from the edges. The inner lining of the filter case appears to be soft cotton, although I am not certain of that.I ran a couple of tests on the filter, one to check its exposure accuracy and another to check whether it diminishes the sharpness of the transmitted image. For those tests, the results of which I have provided, I photographed the lettering on the back of a box of cake mix, under artificial light. In the case of the exposure test, I simply calculated the exposure with the ND filter applied, and made the exposure. I then removed the filter, closed down three stops, since I am testing an ND 0.9 filter, and made another exposure. I found the seller’s stated filter factor of 0.9 to be accurate; both exposures were recorded with the histogram in the same range.For the sharpness test, I used the same two images, with and without the filter, and enlarged them 500%. In this case, I found that the filter did have the effect of diminishing the sharpness. I provided the pictures and labelled them. This may not be an issue if you aren’t enlarging your videos significantly.The physical quality of the K&F Concept ND Cinema Filter, and its coatings, along with the provided case, appear outstanding. The filter factor of 0.9 is accurate as far as my testing determined, but I am disappointed in the reduction of sharpness. That said, that may not be an issue in practice, since, in my opinion, modern digital video capture is overly sharp and unemotional anyway. I’ll know more when I’ve had a chance to use the lens in a live shooting situation.

Like other K&F ND glass (round) that I have, this does not disappoint. No color cast and is at 3 stops. I do like the case that came with the glass, but wish that it fit the filter holder (I know, different brands out there) so I didn't have to keep taking the filter out and handling it. Otherwise, it works as advertised.

Best bang for your buck ND filter. Don't pay $300+ dollars for a filter when these work just as well if not better. I've never had a bad experience with K&F products. No color degradation at all with these filters. No noise at all with these filters when you have to crank up your ISO for dark shoots. Great quality glass, scratch resistant and has 26+ layers. Amazing, amazing for the price. I plan on buying more of these filters from K&F. My next purchase will be the blue filter and black mist. These filters are a must for anyone wanting to make quality videos.