Use the 72mm version on a Sigma SD 14, fits perfectly and saves me many, many different darkening filters. A really great thing, didn't even know that such a thing existed. Previously had 4 pieces of different gray filters, which I could now do all out of the bag. Sounds like a lot of money at first, but I only calculate the expenses from my 4 filters...oh oh I would have gotten off much better here. Now I can !infinitely! adapt to all lighting conditions, a dream.

This filter is perfect for mirrorless digital cameras. It is continuously adjustable from ND2 to ND32 and the camera follows the viewing in real time.
I enthusiastically used this filter for detail photography in bright sunlight and with an open aperture, thereby reducing the brightness.
The workmanship and material quality is excellent, I don't have any complaints about the adjustment mechanism that other reviewers write about.
With me, he now regularly sits on my 18-55 Fujinon and in front of my Fuji XT-20 for cropping with an open aperture.

I'm excited.

5 stars for a reasonably priced product!

As usual, the quality of K&F Concept is excellent. I own several filters from K&F Concept and can only recommend them. The ring adjusts buttery smooth, but not so easily that it would adjust itself. The photo quality does not suffer at all and you get super sharp photos.
This time I decided to use a 58mm filter to cover another lens. As always, it fits perfectly, even if it is rather a cheap lens. I can only recommend the filter. For the bargain hunters - I have always bought the filter in the largest size of my lens (77mm) and then held it in front of all other lenses. This also works very well.

The K&F Concept filter arrives safely packed here. It comes with a duster and a storage bag.

The processing of the filter is really first class. High-quality materials, great handling, a perfect fit and not too heavy on the lens or in the hand.

The filter is simply attached to the lens using a rotating mechanism.

The filter conjures up wonderful images that no longer have to be reworked.

The price is certainly a deterrent - but in my opinion you get one of the best filters on the market. Professionals MUST strike, amateur photographers CAN strike without hesitation

ND2 - ND32 Variable Filter.

Since there is a lever on the rotating bezel, it is easy to operate, and since it
rotates with a moderate load, fine adjustments are very easy to make and is mainly used for video recording. However, it
is good that it does not shift easily even when operating a gimbal.

The variable filter I used previously
sometimes had a bump in the middle which made the dimming more severe, but I
'm also pleased that this product doesn't have that.

The coating is also oil resistant and
oil
is easy to wipe off even if you accidentally touch it.

The case supplied is
also very sturdy so you don't have to worry about it getting damaged while carrying it and it
's great value for money.

The filter came in a very stylish leatherette case, which is a nice accessory and protects the filter stylishly, although a regular plastic case would offer more protection – especially from dust. The filter frame is made of metal and is very well-made and of high quality. It features an orange lever on the frame that allows you to finely adjust the variable aperture. The glass has multiple high-quality coatings. Attaching and unscrewing it to a lens is very easy and secure thanks to the CNC trapezoidal frame. The variable ND filter helps you achieve different effects through long exposures and the filter, depending on the lighting conditions. Of course, the ND32 limits your options, but it's more flexible and faster than having to juggle multiple neutral density filters. We didn't notice any color distortions, and overall, we're very satisfied with the K&F ND filter. It offers very good performance and is really well-made. Highly recommended for the price!

The K&F Concept Nano-X True Color Variable ND Filter ND2-32 is relatively weak, as other filters go up to ND1000. However, it does have a fine gradation in the lower range. I tested it on flowing water in strong sunshine. This only worked manually at f/8-11 and a slow shutter speed. But I have to admit that I'm not a professional and don't know all the tricks. Furthermore, there are hardly any flowing waters in my area that can be smoothed with a filter like this. I live in a flat area. This filter has a 1-5 f-stop range. The same manufacturer also offers a filter with 1.5-10 f-stops, which is even slightly cheaper. That would be the K&F Concept Nano X-Series Variable ND Filter ND3-ND1000. I'd prefer that one for strong sunshine. This one is quite fine for the lousy German weather, i.e., when it's cloudy.

The ND2-32 neutral density filter comes in a very practical leather case. There's a ribbon on the side to help eject the filter. The closure is magnetic. Adjusting the filter is smooth and easy. I use a Canon EOS M10 with a UV filter. This filter was easy to attach. Only the lens cap won't fit anymore.

Conclusion: The quality seems very good to me, and the filter does what it's supposed to. I can't say whether it prevents yellowing, as I lack the necessary knowledge. The product makes a very good and professional impression.

I hope my review was helpful.

This variable lens filter can be changed from ND2 to ND32 and can be easily adjusted with the lever, allowing me to capture natural, beautiful photos without any color shift.

The downside is that when this variable lens filter is attached, the lever gets in the way and you can't attach the lens cover.

I bought this filter primarily for videography, where I usually film according to the 180-degree rule. This means that to achieve a cinematic video image with a certain amount of motion blur in a single frame, you film with a shutter speed equal to 1 divided by twice the number of frames. For example, if I film at 50 fps, I need an exposure time of 1/100th of a second, which is impossible to achieve without an ND filter, especially at wide-angle in bright sunlight.

The filter is also useful in photography, albeit only to a limited extent, as certain situations often require a stronger darkening effect. If I want to create soft water in a stream in bright sunshine, I often use filters above ND1000, as well as if I want to show a busy area deserted.

But as I said, that's also very specific, and in my case, it's about videography. The filter is designed for my 100-300mm MFT lens, which I mostly use for wildlife photography. In testing, the filter showed no weaknesses. I didn't notice any color cast, and there was no X-cross effect. The promised effect of up to 5 f-stops is achieved. Excellent!

The filter comes in a synthetic leather case with a magnetic closure and a "removal aid" in the form of an integrated ribbon to prevent accidental contact with the glass when removing the filter. The case also has a magnetic closure.

The filter itself weighs 43g (weighed) and moves very smoothly with a pleasing resistance across all f-stops. The adjustment aid, of course, eliminates the need for a rigid lens hood, but it can also be removed if you have the appropriate tools.

Technically, this filter, which is the "little brother" of the Nano-X Pro, is also extremely high-quality at a third of the price. The Nano-X Pro series, however, is slightly higher quality in terms of frame and coating.

The price-performance ratio is excellent.

Click to play video
This is a great vari nd filter and gives absolutely zero x pattern on my widest lens, the video I have uploaded is on a sigma 24mm 1.4 art and it's a perfect ND filter with zero colour shift too, really good work from small rig as this outperformas my older but more expensive vari ND filters, it's also well made and butter smooth to adjust, buy with confidence this one is good to go for video over 24mm in focal length.