Bought this hoping to solve the need to stack filters and it’s better then that! It solves the infinite nd filter spinning. With most variable nd filters you just keep spinning around and around, so you end up with those dark x shapes and other issues. This filter has markings and a lever that stops at both ends of the variable nd, meaning you don’t go to far and ruin your shot. Is it the best image quality in a filter (probably not) but it also isn’t 3-400 bucks. So it’s killer for value

I have used numerous filters, from Cokin, to buying several for different sized lenses. And, I do a serious amount of light and strobe painting (do a you tube search, if you're curious). So, when I dropped my super expensive ND filter, I was crushed! Right up until I found this K&F Concept ND, which offers a "Variable Neutral Density". Imagine looking at purchasing an ND Filter for the Typical four hundred bucks (and, that is only for a single fixed ND number)? Oooor, grabbing this well constructed, high quality ND filter that you can adjust to your liking ON THE FLY! Still thinking...
Buy it Bonehead!

UPDATE: I was approached by a company representative and offered a replacement filter. I received it today and did a quick test. This filter seems waaaay better. It doesn't have any shadows in the corners or any black spots when shooting towards a light source. I haven't tried it out in the field yet, but it looks like it'll be alright. Either way, impressive customer service.

ORIGINAL: After reading all the reviews I decided to purchase this filter because my budget was tight. I used it on 24-105 f/4 L lens to take some photos at sunrise and sunset. It's absolutely terrible. There is a black shadow on the right side of the filter that gets stronger with each step. I wish I could return the filter but I've already threw away the packaging:( Will have to throw this filter away as it's completely unusable...

This filter is the bomb! I use it in broad daylight to slow down shutter for that cinematic look. My videos have been coming out nice as of lately. This is actually my second time purchasing this same filter for a different camera. Highly recommended for those who want to master their camera & shoot only in manual...

This filter definitely works as advertised. I researched exhaustively and checked many reviews before purchasing.
Comes in a nice plastic box with some foam cushioning; I added a layer of thin foam in there to keep it from moving around in my bag.
I'm in Florida - took this outside mid-morning, full noon and afternoon, and on an overcast day. Outstanding results, including with flash. On sunniest days I did not crank it up to the maximum setting, just below, and still got great results for both stills and video.
Shooting on a a Canon 6DMII, got three lenses that'll take this 52mm.
Not a 'pro' but half of my income comes from photography and video.
Would definitely recommend this filter - I feel kind of dumb not having gotten it years ago, could have saved many shots.
I found this after seeing the versatility of a variable ND demonstrated in a video, realized I must be missing something. When I looked up that item I was astounded to see that the low-end for that series prices about $250/$300. If you're making museum or some kind of major publishing landscape images you probably don't think twice about that, and I'm certain those pieces are quality. However, if you're reading this then you've already come across a couple of childish and self-important remarks about how this item doesn't compare to 'pro' or 'real' filters. You're on Amazon here - this thing works, give it a try.
Finally - have seen a string of reviews with tantrum-like rants insisting that this filter doesn't work and puts an 'X' on the image.
I'm guessing that's true ... because in the little page that comes with the filter (and the description online) it's clearly stated that turning the filter up to it's highest setting will create this artifact, so they kind of advise you not to do that.
Also, if you cross the street on a red light, you will likely get run over.
It's working for me!

Knowing that you need a neutral density filter and actually using it are two different issues. I'm on the learning curve and results are mixed due to my mistakes, not the filter. Fit and finish is very good, the plastic carrying case seems durable. I'd suggest getting an app for your phone to speed the ND selection process, I've used ND Expert and LEE ProGlass app from the Google Play Store, there are many apps to choose from but these seemed the most user friendly.

Very easy to use, looks very good material. I love the result. Playing with the white balance you can get much better result. I have tested with ISO 100 f / 1.8 and 1/125 sec. when the sun does not let see anything in the camera, and this has allowed me to put it totally dark and also in a desired tone.

Follow the instructions and look at your lens to make sure that you are getting the right size. This will not fit on your current lens if you have a UV filter on there already.
That being said, it works great for shooting in the middle of the day but needing to control the incoming light. I love this filter.

Great product and does what it is supposed to. Shooting with a A7rii and a Tamron 28-75mm G2 it does seem to have a bit of vignetting (possibly due to my settings, may be an aberration other than vignetting as well). The variable ND is definitely nice to have and the range is good for most applications. I especially found it useful in a snowy environment where I wanted to keep the ISO down.

A few gripes I have that maybe unsolvable because 9f the nature of the item: 1) the lens cap only barely hangs onto this filter, potentially a Tamron lens issue, 2) a lens hood doesn't work effectively, the bore of the V-ND makes it so you would have to put on the cover THEN the filter.

Definitely a nice surprise! I expected an average filter for the price point, I am attaching a copy of one of the first 5 photos I took with it in the Smoky Mountains. The first 4 were just figuring out the shutter speed I wanted. Quite pleased, wife happy - can't ask for anything more. Looking forward to many pictures using this 82mm Variable ND Filter with my Tamron 24-70 lens (or a more wide angle when I can afford one) on my Nikon D-500.