As others have stated, when used correctly this filter does not produce the dreaded X. Nor does it have any color cast that I can see. The quality of construction is very good, and the ring rotates smoothly without being too tight or too loose. Quality product. Glad to have it.

Out of the box this filter is well made, threads on and adjusts smoothly. The optics are quality and I was pleased with the photos. I did experience some vignetting when pushed to the limits, but that might have been caused with me having the UV filter still attached and like I said that was at the very extreme end of the filter position. Very impressed with the filter and it's quality. The photos were F8, ISO 100 and 1/160,1/25 and 1.6 sec. Would buy again.

This one helps to keep colors true.
Have you ever tried to photograph purple sport’s uniforms? Without this filter, they often come of digitally as navy-blue uniforms. This filter is a problem solver.
Ever photograph polar bears in the snow? This filter helps keep all the shades of white clear and precise.
I label each box with what to expect from the filter.
It makes it easy to grab and go with the correct filter.
However, when I have time, I enjoy changing out the filters and shooting the same scenes with different filters. It often yields unexpected and lovely results.
Essential filter. Well worth the time and expense.

The filter is thick but it is also larger than 67mm so the effective area is less affected by the thickness. I used Fuji 18-135mm lens to test this filter. When I set the focal length to 18mm (27mm Full frame equivalent) , I did not notice any vignette caused by this filter. Another test I did was set fixed aperture and shutter speed. Only thing that would vary was ISO. I then turned the filter to each ND level on the mark. I could clearly see the ISO keep moving up as the ND index went higher. When I compared the JPG results, I notched not much difference among those shots in term of brightness, color, or sharpness. So I would say that the filter is consistent within its intended stops. With these results, I would give this filter a go. With such a small package for 10 stops of ND, I definitely will throw it into my bag in travel.

I ordered this to use with my favorite walkabout lens, in an effort to get myself back in the habit of taking photowalks on a more regular basis. I had to stop because of my mobility issues, and it's taken me years to get back to a point where I might be able to manage a slow 20-minute walk on less-than-smooth ground, but it's time.

The filter size is accurate and it screws easily into my lens. The coatings are smooth, with no ripples, bubbles, or uneven appearance at any point in the rotation. The ring rotates easily and smoothly, and it's easy to see the glass visibly darken as it's rotated.

The photos come out crisp and clean, without the haze that's often attributable to unpolarized light, and unlike with some lower-quality ND filters, without any hint of a moiré pattern.

One of the better variable ND filters I've used. The build is extremely good for the price. I really like that it is a slim build and doesn't make your setup overly clunky.

This is a filter feature I have wanted for a long time but always considered a multiple filter set, not a single variable filter. To my satisfaction I found this single variable filter works very well and takes up minimum space in my camera bag. The effect given by this filter is also such that I don't have to worry about losing sharpness due to an inferior piece of glass. I use it primarily on my Canon EOS M50.

I have several different sized lens and several different brands of filters. Most are in this price with a couple less expensive and a couple of high priced premium brand name filters.

The majority of my filters in this price range perform like a lower priced filter. Some don’t quite fit on the lenses the way they should, some feel tight when I turn them, and most just don’t perform as a neutral density filter should.

This particular filter surprised me by surpassing my expectations. It feels solidly built. It looks good. The glass looks fine, and you can see it darken as you turn the lends. It’s waterproof, which is a nice touch!

I usually try to give a list of pros and cons in each of my reviews, but this lens filter seriously gives me nothing at all to give as a “con”. I will be buying additional filters from K & F. I see no reason to even try any others at this point.

I hope you have found my review to be helpful!

K&F Concept's range of filters have never let me down and neither has this variable ND3-ND1000 ND filter.

This filter maintains accurate color throughout the entire range unlike other filters I've used, which is a huge plus since it saves me time in post by not having to mess with color correction.

There is no dreaded "X", even when I intentionally went too far. While I'm not sure the stated range is entirely accurate, it is close enough and provides a ton of functionality, especially given the low price point compared to other filters that offer such a great density range.

I don't experience any vignetting with this filter, which isn't as slim as others I've used. But I rarely get vignetting when using the 18-140mm lens that I tested this filter with so my experience may not be applicable to different lenses.

Stops are clearly marked on the filter, and the adjustment is smooth with a little resistance that offers good control while shooting.

That said there is one thing you should know about this filter - YOUR LENS CAP WILL NOT FIT. I wish they included a lens cap with this filter or at least stated this clearly in the description, because you'll have to either print a new lens cap or buy one that will fit over this filter.

For the 67mm filter, you'll need a 72mm lens cap.

Overall this is an excellent value for a high quality filter. I doubt you'll find another variable ND filter with this range and at this quality for a lower price.

The build quality and clarity on this filter is excellent. The adjustment ring is a little snug, but I expect that to loosen with time. I can't tell a difference between this filter and my higher-end ones.