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.

Currently I am using a K&F Concept 77mm Circular Polarizer Glass Filter Ultra-Slim/Multi-Coated for my Canon 24-105mm L Lens.

I really llike this K&F Concept Circular Polarizer over my other previous filter because it really does deepen the intensity of blue skies and reduces and eliminates glare.

My previous version is also normal, while this has a tint via its multi-coating which reduces reflection, glare and improves saturation.

The K&F Concept Circular Polarizer is also made of Japan optical glass and if anything, this provides another added protection for your expensive lens (especially when you don't have your lens hood on).

Overall, I'm quite pleased! Highly recommended!

The quality is very good on this lens. It fit perfectly into my Osmo action 52mm cage. Even my lens cover that came with the cage fit perfectly. The quality of photos and videos produced with the lens on is just amazing. Overall very nice addition to my action cam.

TIP: This filter is made to be able to rotate w/o unscrewing...make sure you realize there is a second/thinner ring that does the tightening to your lens. I didn't realize this at first and thought the filter was stuck on the lens.

I compared this filter to a competitors UV and no filter. Both at F4.0, 50mm, 1/1000 on my Sigma 17-50 f2.8 lens on my Canon. I could clearly see that the colors have more depth and richness to them. It is a lot more evident in the orange and greens of the plants in my photos. It does darken the image a bit but in well lit environments this will be on my lens from now on!

Filter arrived in a plastic hardcase, sealed in a plastic bag. Filter ring has a nice grip knurl for adjustment.

Works very good

Great value. Easy to use.

Great lens, delivered as expected. Quality appears flawless.

Bought this for a new lens and it worked great! For the price, it s a good deal.

Works good...

Very good polarizer