K&F Concept77mm MC UV Protection Filter with 28 Multi-Layer Coatings HD/Hydrophobic/Scratch Resistant Ultra-Slim UV Filter for 77mm Camera Lens

77mm version: This sits on a Nikon 300mmF4 lens, on a D7500 so the APS-C sensor is getting just the perfect centre focus region.. The lens is excellent, and I did a back to back comparison test - pixel peeping right to the edges..With a focus chart, there is literally zero difference. An excellent filter.The thing is also lovely and thin, and the grip on the edges is really good - the matt finish is also really good.Not expensive, but performs perfectly.52mm version: this is on a 35mm f1.8 prime, on the D7500. Flawless. Tried to be a little more rigorous in testing with this to see if there is any vignetting etc. Nope. Excellent and inexpensive.

I've switched to K&F UV filters from a "competing" brand.A couple of reasons:The filter build quality is superior. These have better "texture" to the metal making them easier to screw and unscrew. The coating looks superior, and I have not noticed any degradation in image quality. Image quality between UV / SKY1A filters is so subjective I won't go into any discussion. Suffice it to say these have no noticeable degradation to picture quality (and I do a lot of macro & wildlife, both ends of the distance / lighting spectrum). Further, I am fanatical about protecting my lenses. The threads on the lens barrel are easily damaged by a drop and the glass can be scratched. I'd rather replace a filter than a lens any time.K&F has a "better filter".Recommended.

Great service and product looks to be great quality.

This K&F Concept 77mm UV filter arrived with smudges on the backside of the filter, the side next to the front element of the lens. I did not notice the smudges when I installed the filter on the lens. Only later did I see them, and I assumed they were on the front of the filter since it was the only exposed side. At first, I thought the smudges could not be cleaned. After removing the filter from the lens, I was able to clean the smudges on the backside. It is disappointing that a new filter ships with smudges.

Took four pictures after mounting UV filter and checking lens cap for fitting.So far along, everyone looks good.Cleaning clothes work but it is difficult to got rid of small dust particles on UV filter.