Anyone who likes photography knows what you use an ND filter for. Since my attention is the landscape photography I can not avoid working with such filters. I ordered this one from K&F for my full frame camera.

I was just tired of filling my backpack with ND filters of different strengths. So the Nano-X Pro came in handy. To use it on several lenses I ordered it in the size 77 mm. I then work with step up rings to be able to use it on smaller lenses.

To say it right away: The optical quality and the quality of the images has flashed me! The workmanship is excellent and very successful. The lens thread is top clean cut.
The filter is adjustable from ND 2 to ND 32. The larger steps (f stops) are marked on the ring and easy to read. It can also only be turned in this range of 1-5. Below or above it does not work. So you always know by the stop what you have set.

The 77 mm. Ring brings 93 gr. on my kitchen scales. Everything is solid and feels very good. The setting runs well with slight resistance. So it should be.

The optical quality is absolutely flawless and even in difficult lighting conditions the filter delivers top. Chromatic aberration or color gradients into the green, magenta or anywhere else I have not been able to determine even when pixel peeping. Even with foliage or firs in backlight and with reflections from dew, the quality of the filter is unsurpassed. Finally a ND filter that does justice to my limited lenses and the full-frame sensor. The frame thickness with thread is only 9 mm. Without thread 0.63 mm. So you can use the filter on wide angle lenses without edge shading.

Thanks to the two screwed brass handles and the ribbing of the ring, the filter can be adjusted very sensitively.

Conclusion:
K&F Concept has delivered a top filter here. What good is it if you put thousands into lenses but then bad filters make the work difficult or lead to lousy results? From me clear 5 stars+. I hope this is useful for your purchase decision. Also the price is relative because you save at least 4 ND filters.