My first experience with the K&F Concept filters was with the purchase of a light pollution filter I've been happy with, particularly liking the grippy knurl added to the edges of the filter. After accidentally scratching my Hoya NXT Pls CPL 82mm filter which is more than double the cost of the K&F filter, I decided to purchase the K&F Nano Series CPL filter and see how I like it. Moreover, I also chose to go ahead and buy a 95mm version as well, to replace a Pro Optics (Adorama house brand) filter that I thought might be a lesser quality filter. Both K&F filters arrived today and a visual inspection of them reflects a quality product as I expected. However, one minor complaint is that I like the round K&F filter case which as a rigid plastic insert that appears to be grooved to support holding any of various sizes of filters securely in place in the case....that is, perhaps for a range of filter sizes, K&F may be using the same case to save manufacturing costs. However, while the 82mm filter arrived with that same case, the 95mm filter was in a more common, square plastic case with foam cutout to hold the filter. Still fully functional, just not as nice as the case provided for the 82mm filter. I don't expect to see any problems with the cheaper case, but it is the type that frequent use could find the plastic hinge wearing out eventually; I simply favor the 2-piece round case of the smaller filter.

Fast delivery, well packaged. Quality of manufacture is excellent. Filter lens works excellently on camera. Would recommend.

Ths CPL turned out to be great. I was afraid that the green nano-coating could cast a greenish tint on the image. I haven't noticed any annoying green tinting although it does have a slightly warmer and maybe yellowish look. Nothing that can't be controlled with proper white balancing and some minor editing. I find this CPL to be really good for the money.My only issue: my lens cap seems to not fit properly over this filter. I can still use it but it falls off easily. Keep this in mind.EDIT: I'm taking a star from this because taking the filter off is a nightmare. I use a high end UV filter from B+W on my favorite lens and got this K&F cpl for that same lens. Before purchasing i asked and made sure the filter was not only stackable but good to be used over any filter, including my specific UV filter reference, and i was told, here on amazon and other sites, that it was totally fine. well, I'd love to have some of those advisors to try and take off my cpl from that B+W filter. It's like they fused together. Moreover... I had an accident yesterdayand the cpl got some mild scratches. I'm trying to take it off so i can decide whether to get a new cpl or not. Well, no matter what i try (and I've even tried the rubber band trick K&F has on youtube), its not workingLong term review: after a few days i managed to take the filter off. The scratches were minor so i kept it. I've been using it quite often ever since and now I'm super careful not to tighten it too much. Learned my lesson the last time. I still like it, but it lacks some power, specially when taking pictures of stuff in the water. It works, in the sense that with patience and a very good angle, you can see stuff under the surface, but it still leaves sone glare and reflections. When i use it on other super shiny surfaces, however, it's quite good. I know this isn't an expensive filter so i still recommend it for the money, but if you are serious about it, you'd better save some extra money and get a higher quality filter. I don't earn in dollars, so to me it's a fair steep difference between this tier of cpl (which i consider affordable and acceptable) and the next level. But i really want a better one and will eventually replace my K&F filter

I have third party CPL with much stronger effect.

Flat and distortion free. No discernible color cast.

Use this filter a lot outdoors for cutting down on glare. This is a high quality filter and does not diminish the quality of my lens even slightly.

I'm using this filter on my telephoto lens (200-600) and it works great.

Used to help reduce some glare from snow and it helped a lot. Fit great threaded on snug and smooth. Perfect fit.

For the price and the lens it was wanted for, it's okay. Sure, much better out there but associated with a leap in cost. Okay for the amateur photographer but a professional would need better.

Felt professional. Looked professional. Image quality looked perfect.