originally purchased the magnetic holder for my VND filter and was not satisfied. It was too easy to accidentally run off (I'd done that several times before). This filter is screwed on, but I know it won't fall off. I didn't notice any significant vignetting around the edges, but I also use Osmo action cameras, which have a lot of vignetting, but it doesn't bother me. The sliding mechanism is sensible enough to keep me moving while I'm outside trying to find the best setting for a picture. I was worried this wouldn't be enough on our recent trips, but for me it's worked out pretty well.

I've been wanting to buy a VND filter for a while, but with so many brands... I couldn't decide. Thanks to the low price, I finally made the leap with the K&F. I thought, “At this price, I’m not losing anything. Plus, I can return it if I don't like it. Let me tell you, I couldn't be happier. The built-in polarizer ensures beautiful colors, as you can see in my shots above. It almost never leaves my lens. I bought it for my RF 50mm f1.8 and now I will get one for all my lenses.

This is a high quality circular polarizer variable neutral density combination filter from K&F. I used the 77mm to cover most of my lenses using step up rings. The smallest filter size is 52mm as shown in the photo. The filter is excellent for everything it does and it is inexpensive. It's much more convenient than separate filters; it is quicker to use and requires less carrying in your pocket. This also works for some wide angles, which would be a problem when stacking multiple filters. The build quality of the filter is excellent. A leather storage case is included. From 4 stops onwards there is a slight vignetting and color shift, which increases with increasing ND filtering. This is expected and can be fixed in post-processing if desired. Image sharpness and sharpness are not affected. This filter outperforms other CPL+ND filters I have used.

This thing is niiiiiice! High quality! And the packaging is A1! It’s just well thought out!

This is the variable ND filter and polarizer.
The CPL filter eliminates light reflections on surfaces, cars, water, glass, and also enhances the colors of the sky, leaves, asphalt, etc.

I personally use it for video so I don't lose depth of field by closing the aperture (from f9 I can now go to f2.3 without burning the images due to too much light).

About the image quality. Well, excellent: There are no dominants, no chromatic aberration, no loss of sharpness or the horrible X of gradual ND filters.
I have a very expensive polarizing filter and hardly notice the difference with this one.

Price and performance are top !!!

This is a premium combination filter from K&F that combines an ND filter and a circular polarizer. The build quality is excellent. The machining and anodizing of the buttons is very good. The selection doesn't move, but overall it's pretty easy to move. The knurling on the mounting ring ensures that it adjusts easily enough when adjusting the ND/CPL function to prevent it from twisting off. However, using this filter is a bit difficult and not as fast as using the standard filters separately. When you move one ring, it usually moves another ring. So you have to hold a ring still with one finger once you make a selection and then make the other selection with the other finger. This makes it very difficult to use on the go or while holding a fairly heavy lens and camera combination. It is best suited for landscapes/tripods rather than scenes where the light changes drastically. It can be set for a scene, but changing it requires some work. Sharpness doesn't seem to be affected too much when the filter is activated. However, there is quite a bit of red/purple color cast. In very bright lighting conditions there may be some purple/red flair. So make sure you are aware of this. This filter works like a combination filter, but has more limitations than using two separate filters. There are still situations where both are needed, it works well. I wish they would stick with the plastic case instead of the leather case they used for this filter. It's bulky and just doesn't stack as well as the plastic cases. The compromises make it a casual use filter for me, but overall in situations where it is used it has worked well.

I usually use fixed ND filters with a separate CPL but my filters went missing on a shoot. Instead of replacing them all, I decided to try this combo filter. I had mild expectations, and it has exceeded them. I thought it would be thick and possibly vignette. It is actually thin and even when stacked with a UV filter no vignette. The clarity and build are exceptional. It also comes with a really nice filter case. I do have one criticism on the design. There are 2 finger tabs. I figured on was for the VND and one for the CPL, but they are both for the VND. To adjust the CPL you have to turn rim of the filter, which is hard to do without moving the VND. A finger tab on the CPL would be helpful.

This is an excellent quality circular polarizer and variable neutral density combination filter by K&F. I got the 77mm to cover most of my lenses by using step-up rings. The smallest filter size will be 52mm, seen in the photo. The filter is excellent for all it does and it’s reasonably priced. It’s much more convenient than separate filters; faster to use and less to carry in your bag. Also, this will work with some wide-angles that would be a problem when stacking multiple filters. The build quality of the filter is excellent. A leather storage case is included. There’s some very slight vignetting and color shift starting at 4 stops which increases with more ND filtration. That is expected and can be dealt with in post processing if desired. Image clarity and sharpness is not affected. This filter outperforms other CPL+ND filters I’ve used.

I put this on my Nikon z30. It's on my 24mm 1.7 lens. Really helps at night and during sunny days. Does a really good job at reducing reflections.

The filter fits my lens well and screws in easily. The lens cap fit on the filter, but the flange on the filter was too large for the lens hood to be used with. Both the polarizing filter and the ND filter rotated smoothly. The polarization filter reduced glare when rotating. The ND filter allowed me to slow down the shutter speed and still get the same exposure. This would be great for giving waterfalls that thin effect, although there aren't many waterfalls here in December. I noticed a purple tint at the darker end of the ND filter, so apparently it's possible to go too far with neutral density filtering. Other than that, I'm happy with the filter and look forward to using it more in the spring.