I bought this filter, tempted by the low price and the fact that it is small and light and allows me to have several panels together in a single accessory, since I already have panel filters and in addition to 150x150 that are really uncomfortable too are wearing.

The product looks very well packed in its case, it is very light and made of metal material with the various notches that indicate the ND phrase. Maybe I would have preferred to have actually written about how many stops there were without having to bother trying to figure out how many ND I was each time. (but maybe space doesn't allow it).

I am satisfied with the purchase I made because it exceeded my expectations. In fact, I ran some unpretentious tests on the fly, and the result I would say is not bad at all.. I
tried it with a focal length over 50mm, where I had no problems and the picture with a uniform exposure without a halo results, but it must be said that I also only tried it at ND400 without trying the intermediate stops so I couldn't tell what happens at a bottom stop; Unfortunately being in the middle of the day didn't allow me to do other tests.. (Of course I'll update if I can by adding more details).

Finally I don't think there is anything better in terms of quality/price, at least for the ones I've tried and K&F is improving year after year... I'm attaching a few photos to remind you of

the product and the draw attention to the result...

Very easy to use, looks very good material. i love the result. If you play with the white balance you can get much better results. I tested with ISO 100 f/1.8 and 1/125 sec when the sun doesn't show anything in the camera and this allowed me to set it totally dark and also to a desired tone.

I was surprised at how good this under $20 Vari filter turned out to be! I needed a Vari-nd for my trip to Thailand as I only had one lens with me (Blackmagic Pocket Cinema with a Panasonic 20mm 1.7). I usually use the Hoya ProND (one of the very best ND filters ever) but I needed something more practical for a vacation as wearing NDs wouldn't be. Looking at the footage I shot I'm very glad I decided to purchase it as I haven't noticed any toning yet (despite shooting raw). Remember that there is a rainbow effect behind certain glass surfaces.

The common wisdom is never to buy cheap ND filters! Always Pay Hundreds of Dollars! Or you know, get this one (great so far for video in ridiculous sunlight - ISO 200f/1.7 = crystal clear skies, not a pixel overexposed) and use the money saved to buy another lens or peripherals. Fits perfectly with nice, tight threads, the variable spins smoothly, no green cast or splotchy lines I could see even at 4k zoom, and comes in a cool protective case that fits my pocket like a glove.

I have a tripod and an EF to 4/3 adapter from K&F Concepts and these guys haven't disappointed me yet. Quickly becoming one of my favorite companies.

The thing works great. Smooth adjustment, solid construction. Color looks just right. Cheaper than some competition. Can really control the incoming light without having to change the settings in the camera, so you can play with an aperture of 1.2 outdoors or just fast for run and gun. Here's a trick, get a bigger one and some step down rings so one filter can fit multiple lenses. ;)

I found this filter to work as advertised. I think if you're getting into neutral density photography or video this is a great place to start. I'm now switching to fixed filters and changing them as the light changes instead of using this adjustable one, but I think this is the best place to start

I purchased the K&F Concept 46mm Variable ND prior to my vacation in San Antonio and was super impressed with the performance of this budget filter!

Any aspiring photographer knows how difficult it is to film and shoot in bright sunlight without overexposing everything. This variable ND was the easiest answer to my run and gun film style while I was out shooting my vlog on my vacation.

I definitely recommend this product to people who need lens filters for their shots. Comes in a nice protective case and easily fits in my camera bag!

I am very satisfied with this filter as it was a one time purchase as I also bought the adapter rings to attach it to the camera and the truth is that it is very good. Today I shot outdoors with the filter on and a pass, it's also appreciated that it's variable.
I'm even looking at a polarizer from the same brand.

Knowing you need a neutral density filter and actually using it are two different issues. I'm on the learning curve and the results are mixed because of my mistakes, not the filter. Fit and workmanship are very good, the plastic carrying case makes a robust impression. I would suggest getting an app for your phone to speed up the ND selection process. I used the ND Expert and LEE ProGlass app from the Google Play Store. There are many apps to choose from, but these seemed to be the most user-friendly.

Do what it says on the tin. Well built. Easy to set. Has a certain polarizing effect. A must for sunny days. I really don't understand why a "layman" should spend more than 30 euros on ND filters. The quality of K&F is very good and the price is even more impressive, I recommend it!