I ordered three of these variable ND filters for my Canon lenses and have found these filters to be of excellent quality. The filters operate in the same way a polarizing filter does. The outer rim of each filter is knurled for easy grip and adjustment. The outer lens is slightly larger than the inner lens which accomodates the view of wide angle lenses.

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.

Best non-Canon lens for this price. I used it for night shots and also for capturing northern lights. It's my favorite lens. The build quality is also great. It's manual focus, but you get used to it after using it for a long time. I've been using it for 3 years and there are no problems with it.

I am very pleased with this system and the quality of the filter lenses. It is wonderful for very quick changing of filters. Unfortunately I accidentally lost the ND filter the first time I went out and did not realise it until I was back home. My friend had zipped the bag they come in, and I, thinking it was still open and more concentrated on trying the one on the camera. unzipped it. So during my wanderings, the ND fell out. I did eventually manage to replace it, and received a magnetic lens protective cover as part of the order. I am made up now. I do recommend this system and it has the filters that I use, perfect.

I have to say that I have never used filters - this is my first try.
I like ND filters. I don't see any discoloration or Sharpnes loss in images.
I wish they had a set for 92mm lenses.

I have come to rely on K&F Concept for a number of filter types for my many lenses. They are well made with quality glass and I have yet to find any real faults or negatives in these great value filters. You would have to pay a TON more for filters that are only slightly better than these!

This variable ND3 to ND1000 filter provides highly capable ND correction from 1.5 to 10 f/stops. It is a 67 mm filter that is widely used...especially for the majority of Tamron lenses as well as a plethora of Sigma, Sony and Canons as well, which makes this filter an even better bargain.

The variable range is done simply by rotating the front dial of the filter until just the right ND level is found in the viewfinder. The filter features 24 multi-layer coatings to provide the clearest and distortion-free optics, using Japanese glass (Excellent) and precise CNC machining.

I can honestly say that this variable ND filter is almost as good as filters that cost as much as five times more. Construction is very good and the filters mount to appropriate lenses without drag, rubbing or other issues. Simple operation and fantastic results!

All in all, and especially at the value price, this set earns an easy FIVE STARS with me, and I can honestly and heartily recommend the set for your appropriate lenses.

I bought this adjustable ND filter to use on my trip with my Canon EF lenses. It worked like a charm and allowed me to capture some beautiful scenery!

Seriously this is the best filter I have ever bought for my Canon 16-35. This smashes other ND filters out there! No banding or weird "X" stuff what so ever. Affordable, well-built, and preserve the great image quality you strive to get. You cannot go wrong with this filter. I cannot wait to buy more for my other lenses!