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'm thrilled ... I think the combination of ND and polarizing filters is brilliant; the brand and this idea made me buy it. the polarizing filter works perfectly Well - I would buy it again; Especially with water photography, this filter serves two purposes, which triggers some fascination in me

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.

The putter on the frame comes in really handy. Honestly, I think that a lot of filters need something like this to make the experience of adjusting the filter much better.

In the past, having to screw on two different type of filters on my camera seemed like a daunting task, and with this filter one of those steps is removed, so I'm grateful for that.

I absolutely recommend this if you're looking to have both an ND filter and a CPL filter in one. It saves you a hassle!

A truly excellent product, practical and at the same time very delicate

This is a really nice design for us landscape photographers. A 5-stop variable neutral density filter with a circular polarizing filter built in. It’s all packaged in a single thin package, made from high-quality glass, that’s also scratch-resistant and waterproof. In the field, it’s easy to work with, very convenient, and no filter stacking is needed. It operates smoothly, just twist to adjust the ND or the CPL. The filter comes in a very nice case and is well-packaged. Overall, a great design that is an excellently constructed tool that should last you a lifetime (barring accidents or abuse).

I have only taken a few test shots outdoors, but so far I really like this cpl+nd filter. When I took photos of my backyard, the images were sharper and more colorful where I used the lens.

I am very happy with it. CPL+ND4-64 filter that is exactly as described.