love it, very well made, quality glass, and great fit

When I ordered the K&F variable ND filter, I wasn’t sure what to expect in terms of quality and the coloring that would be achieved when my images were rendered. However, the colors do not shift at all, and I was pleased with how nicely they pair with the Sony A7iii and A7riii. As an owner of both Polar Pro and Tiffen filters, I must say this filter is a cost-efficient product, coming in at half the cost of the Polar Pro filters I own. Even better, is that this filter has hard stops so you don't get that X when you go beyond the filter’s limit. If you're on the fence about ordering this product, I highly recommend trying it out. Below, I've added a couple images where the K&F variable ND filter was utilized- one shows the filter on my Sigma 135mm f/1.8 Art, and the other demonstrates a portrait I took while using it.

I use this both in the studio to drop my F-stop, and for Video. Used it on professional shoots with my RED, and smaller shoots with my Fuji. Haven't pixel peeped it, but during my edits, I notice no desegregation or X. The best variable I've seen, and absolutely a steal for the price.

Great the filter. No X. Great price. Also comes with a case

-I’m surprised and impressed by the quality and nice feature of this filter-The lens uses German glasses that’s built as a versatile adjustable filter from 3-stop to 7-stop (ND8 to ND128). The frame is built with quality aluminum for smooth adjustment and thread on/off. It’s also stackable so you can screw it on another filter, say another K&F Concept CPL.-Nano coating for water/fingerprint/oil/scratch proof. Both sides coating that ensures the quality of the image. I can’t believe it has all these awesome features come with a low-cost price that saves me $100+ from other major brand filters.-I use the Kodak Color Control Patches for my testing-I can really achieve 3-stops all the way to 7-stops filtering, as seen from my shots at 1/30, 3.2, 5, up to 8 sec.-I really don’t see “X” cross imaging as promoted-No Vignetting at corners thanks to the ultra slim rim design-No image distortion by comparing filtered image on a test pattern-Finally, I posted a beautiful image with f/22, ISO-100, 6sec using the filter at the 7-stops (ND-128).

For the money you can't beat this product, especially for video. The variable control allows for a much better control over lighting conditions that gain (or iso) alone. Love it and would recommend when you need to shoot in direct sunlight.

The only negative part is that the lens shade doesn’t fit

Overall I am happy with this filter. I did a lot of research when looking for ND filters for my Fuji XT3. I had three goals when choosing an ND filter.1) I can get good long exposures2) There is no noticeable color shift3) No vignetting or distortion on my 16mm & 56mm lens.The three goals above have been met. Provided you are not taking pictures during the hours of 11am and 4pm on a sunny/bright day and expecting more than 4-second exposure then this is great. Outside of these times, you can take up to 8minute exposures. I am a little concerned that this is not actually an ND8 to ND128 filter (reasoning below).I have not really noticed any major color shift. I would say if anything that it shifts ever so slightly to the cooler tones, but nothing that basic color correction cant handle.I am not really getting vignetting for most of the time even on my 16mm F2.8. I have noticed once or twice on some pictures however. I am using a step-up ring from 49mm to 62mm.I only have one complaint. The case is of poor quality and not fit for purpose. It is a cheap circular plastic case that is far too big for the 62mm filter. It's probably designed for the biggest lens they make. There is no padding of any kind so the filter moves freely inside the case. Not what I expected at this price point.There is also no indication anywhere that this indeed an ND8-ND128 filter. Nothing on the packaging or the product itself. Even the picture on Amazon shows it as an ND2-32. So I am a little concerned this is actually the filter I ordered.Hopefully someone from K&F will follow up on this?

The darker version of this is utterly indispensible for LOG video with high ISOs forced by the camera, combined with fast lenses you'd like to open up for depth control/"bokeh". And only the wildly expensive PolarPro has a similar option. And while I suppose the PolarPro might be somehow better - I'm simply not rich enough to find out! In the meantime the K&F has served very well. I use this primarily on a Fuji X-T3 with f1.2 and f1.4 prime lenses, shooting F-LOG at the required minimum 640 ISO. Secondarily on a Fuji X-H1 (800 ISO LOG!) and even a Nikon D750 for occasional stills.** Hey K&F! Do you read reviews? I wish you offered the dark version in smaller diameters (e.g. 62mm) as I'd get another to use with the majority of my prime lenses with no step-up ring. **