For the price, its great value. It does what it says on the tin and I haven't spotted any great colour shifts yet.

Great for DSLR filming. In fact, it’s a MUST!

This is amazing, what a difference it makes trying to take a photo with the correct setting means outside your photo will be blown out.

This is simple to fit and works extremely well.
I mainly use for filming but have not had any issues and has taken my filming to the next level.
Comes in a nice case so can be packed away in my bag.

I like this ND filter a lot.

I had been meaning to buy a variable ND filter for my 24-70f2.8l for a while. When I heard about K&F filters; having tried a 3xnd filter kit pack that I was impressed with; especially at the price. I looked at K&F's other products and found this more than reasonable price ND filter and had to give it a go.

The filter is shipped from China; so its not something to order if you are in a rush - but when it did arrive I was blown away by the quality of the presentation. The filter was packaged inside a well designed; expensive looking, cardboard outer package and then a hard plastic inner with a foam sheet to allow it some protection.

On opening the pack one disadvantage to this filter immediately manifested itself; the front element isn't 77mm so your lens cap won't go back on the lens with the filter mounted. The filter mounted smoothly onto my lens. The variable darkness is achieved by rotating the front element; as you would a circular polariser. The K&F filter spun smoothly but with enough resistance to keep the darkness you set so knocking it won't change the setting. One disadvantage to the design is the filter doesn't have coded ND values so there is a bit of guesswork to get the right exposure for stills.

I tried the obvious and took an image of a plain white wall at various ND settings; and there was some minor differences in the brightness of the photo - it was a bit lighter at the edges of the frames. At its darkest on long exposures; the 6d went red shift but this is correctable in Lightroom (and made much easier if you use a colour checker passport.) If you zoomed in on the plane white background you could see some variations in darkness; and ultimately pixel peeping at maximum darkness a mesh. That said taking pictures of something more interesting than a wall the effect was lost in the detail of the image.

I rarely shoot video so for you dear reviewer; I shot some test video of the same white wall. I don't have any fancy video editing software and just watching the video back in lightroom; the darkening effect was pretty uniform across the photo. As with stills if there were any criticism it is very minor and that the corners show up brighter than the centre of the frame. The majority of the frame being uniformly dark. There was no patterning showing in the video.

Using a standard ND filter definitely gave a more even darkness to stills but I am planning 3 long trips this year and carrying 5 ND filters everywhere felt like a chore. Now I just need one. If i could I would ding 1/2 a star for the front element size not being 77mm but its a minor inconvenience in the scheme of things.

Great ND filter. Variable. Up to 400ND. Very good quality. Very happy .

First variable ND filter purchased (all others I have had have been static) and what a difference it makes!
So easy to move around, and not having to carry more than one per lens is a real space-saver in the bag!
I've experienced no false colour or the infamous X on any images (although I don't use this all the way closed!)

Comparing it to a friends premium ND (I won't mention the brand), I could not see a difference at all in image quality. However, the premium ND was a bit stiffer to move around, so it felt like it would stay exactly where left. The K&F one does feel like it may loosen up over time, although this hasn't happened yet a few months in!

Makes a big difference in capturing a bland sky which otherwise would be featureless.

Great picture quality and value for money

I've been using the filter for over a month now and haven't had any problems with it.
It does show some spots, but only if you turn it towards very dark filter.
From the reviews I watched before purchasing it, for its price point it might be the best choice.