I've had two other variable NDs, and this one is an improvement. There is a bit of a color cast, but it's so minor that it's not bothering me, and it's relatively easy to fix in post if needed. I've not yet seen the common blue X in any images where i would have expected it. Big plus there.

One thing i would appreciate for any of the rotating ones like this is a brass thread. Sometimes filters get overtightened and a filter wrench is needed to remove them. Brass usually avoids that happening, surely realistic with the price of these. They are not priced as cheap filters.

I own many K&F filters. Every single one of them is well made and fit my lens like a glove. They are all made of quality materials. The optics on this lens are premium and worth every penny. Another great filter to add to my collection. If you don't have a ND/CPL, I highly recommend trying this one out. It does not disappoint.

The presentation of this filter is very good.

I find it an essential accessory for sunny days.

It has a regulation with values ​​from 1-5.

It is for a 67 lens, in my case I am going to put it on my 85 F1.8 Sony and on my 18-70 F4.

It is easy to install, since it is only threaded.

K&F has another great product here with this variable ND and CPL filter combination. For most situations, I prefer a combo filter like this one just for the sheer convenience of it when I'm just trying to get good shots in the moment and not wanting to fiddle with separate filters. The finger tabs on the ND filter make it really easy to adjust and the filter stays in place one you get it set without having to worry about it moving around on you. The filter comes with a quality soft case that protects it well for when it gets tossed back into your camera bag. Overall, I'm very pleased with it.

A filter like you rarely find.
Careful quality with a very well-made box worthy of a jeweler.
The adjustment is done smoothly, the filter offers a wide range of adjustments.
For my part it is mounted on a 28-80L f2.8.
Extremely satisfied with the result.
Friendship, Laurent"

Another home run from this company as they make great filters. Screws on nicely and pictures are vibrant.

Using the filter is a breeze. The variable ND aspect ranges from ND2 to ND32, giving you a wide range of light control options. It's like having multiple ND filters in one. Adjusting the density is as simple as twisting the filter, and the markings are clear and easy to read. The integrated CPL function is just as user-friendly. By rotating the outer ring, you can adjust the polarization effect, which I've found incredibly handy for reducing glare or enhancing the sky in my landscape shots.

"Very high-quality filter: combination of polarizing filter and gray filter. Who needs that?
I think everyone who wants to take good photos. The polarizing filter reliably reduces reflections and makes colors (e.g. slightly cloudy skies) shine much more intensely. The pictures already show the simplest use. The gray filter enables longer exposures even during the day. Of course, you need a tripod for that.

By turning in one direction you first set the polarizing filter, then you can make the gray filter increasingly darker.

The workmanship is very high quality, which also justifies the price. Packed in a high-quality cardboard box and an artificial leather box. This is a great gift for photo freaks.

Take a look at Siegfried Eichhorn's video on YouTube about ND filters. Then you'll press "Order" at the latest!

With suitable adapter rings I can now use the filter on all my lenses. I am impressed by the quality."

As a filter, for both polarizing and variable ND, this is a solid 5 stars! I'll explain 4 stars to get this out of the way—the filter is large in diameter, and those orange grips stick out even farther. This will not allow any of my lenses that use this size filter use their lens shades at the same time. Also, (and this is probably necessary, to avoid vignetting), there are no receptical threads in the front—so you can't use your lens cap when the filter is attached. I have a feeling that this larger diameter is an issue with most variable ND filters though.

Now that those issues are out of the way, I can speak to the positive attributes. I have a number of very good polarizer and Neutral Density filters (none combined) from top manufacturers. I've avoided variable ND filters in the past—pretty much every review I've read mentions an "X" that appears (as a darkening) once the filters are above 3 or 4 stops. But, since I've used several of the higher grade K&F filters (UV and ND) and have seen how good they are, I thought this one was worth a try.

First the polarizer. I've attached two birdbath photos—one without and one with the filter at maximum effectiveness (with the ND set at 1). (Note that without the polarizer, I was focusing on the reflection on the water surface, so the birdbath and surroundings are out of focus. This also affected the overall exposure.) To my eye, this is working very well, without creating undue color casts, and the exposure is even across the image.

Next, the ND The first shot is no ND filter at all, and the second shot is the maximum 5 stops of this filter. There is a very slight color shift between the two; it's possible that if I didn't have color temp. set to auto on my camera, the difference might be more apparent—as it is, the correction needed would be easy in post. The main issue to me, is that the color shift is even across the image. And, the only ND filters that I have (and remember they are fixed ND, not variable) that have less color shift than this cost more than this filter. (And, they are just a single ND and there is no polarizer in them, either.)

The filter comes in a very nice case; I'm undecided if I like this better than the typical top and bottom lock together "caps" or self hinged snap box that all my other filters come in. It doesn't take up more room, and it's fun to pull the orange webbing and watch the filter lift out of the case.

I liked the image quality, I did not like that to move the cpl is not so easy and the price is not very accessible but good product.