This variable ND filter from the K&F Concept brand was kindly made available to me free of charge as part of the K&F Concept Vine program. First of all, I would like to thank K&F Concept and, of course, the manufacturer.
However, the fact that I received this product free of charge has no effect on my review.

First of all, you have to say that you get an incredibly well-designed product here, which is reflected in the type of packaging. It is very high-quality and attractively designed and gives you the feeling that you have received a quality product here. In particular, the storage bag with magnetic closure is a really nice bonus that you don't often get included in this quality. With a simple strap on the side, the filter can be pushed up from the pocket and removed.
It is also very nice and a nice idea that you can reuse the inlay of the packaging as a small picture frame. A small cardboard sheet is included for folding, on which the quick instructions for folding are also printed directly. This then becomes a small stand, which can be glued directly to the back of the inlay. The small but somewhat stylish picture frame is ready

My buddy and I have been running a channel on Youtube for several years and have also become partially self-employed through it. We produce content for companies and we have now put together a lot of equipment for this purpose. When it comes to ND filters, we have been in the cheap segment so far and have relied on fixed filters, as we haven't heard anything good about the cheap variable filters.

We now use square filters with matte boxes for larger productions. But especially for smaller orders, where we need a lot of flexibility, we rely 100% on the Nano-X Pro. This covers exactly the area that we need. The optical quality of the images is really great and there is simply no falsification. In some cases, we also use an adapter for square filters after the Pro ND. This works because the Nano-X Pro has a thread into which you can screw additional filters.

In theory, it is even possible to use it in conjunction with a matte box and a rectangular filter. The options are very varied.

I can only say words of admiration about the workmanship, simply terrific. As soon as I unpack it, I have the feeling that I am holding a super high-quality product in my hands. The workmanship is impeccable and the case makes an equally high-quality impression. The adjustment of the filter is very smooth and the filter has not even tilted so far.

I can make my recommendation without hesitation. Anyone who makes the, admittedly quite large, investment will be rewarded with quality and visual material, which definitely justifies the price. Anyone who claims that a cheap filter does the same in this regard has not yet addressed this issue in detail.

Los filtros K&F suelen ser inmejorables en cuanto a relación calidad-precio y este filtro no es la excepción. Lo uso en una Sony 18-105 f/4 y nunca me decepciona.

Graufilter sind in der Fotografie nicht wegzudenken. Ganz besonders in der Landschaftsfotografie nutzt man sie ständig. Man kennt diese tollen Bilder mit dem fließenden Wasser, das so „fluffig“ weich aussieht – Für sowas z.B. braucht man einen Graufilter.

Ein Graufilter, oder auch „ND-Filter“ (Neutraldichte-Filter) schluckt das Licht, so dass man länger belichten kann. Durch diese lange Belichtung und der Bewegung des Wassers sieht es so toll aus.
Durch das Fotografieren mit einem Graufilter wird das auftreffende Licht abgedunkelt und man kann besser in sehr hellen Umgebungen fotografieren.
Wenn man bei heller Umgebung einen Graufilter nutzt, kann man im Gegenzug mit einer weiter geöffneten Blende oder längeren Belichtungszeiten fotografieren.
Durch das Fotografieren mit einer längeren Belichtungszeit kann man schöne Effekte erzielen.
Normalerweise werden Bilder überbelichtet, wenn man eine besonders lange Belichtungszeit wählen.
Mit einem Graufilter kann man dies verhindern und trotz viel Licht mit langer Belichtungszeit fotografieren.
Das hat die Folge, dass Bewegungen unscharf werden und ineinander verfließen.
So kann man zum Beispiel Gewässer oder Wolken, sowie schnell bewegte Objekte besonders kreativ darstellen.

Der K&F Concept Nano-X PRO Serie ND1000 Filter besticht mit hervorragender Qualität, er wird in einem schicken Case geliefert (Magnetverschluss). Dabei ein Reinigungstuch.
Ich habe auf die fünf Bilder geschossen, diese habe ich nummeriert. Der Unterschied ist klar zu erkennen.
Der Filter ist sein Geld wert, er ist einfach aufgeschraubt und sogar mein Objektivschutz passt noch drauf.
Dieser Filter macht Lust auf mehr und bekommt von mir die volle Punktzahl!

A casa ho già alcuni filtri, tra cui il K&F Concept Nano-X ND Filter 77mm Variable Grey Filter ND2-32 a 75 euro, che uso sul mio grandangolo, ad esempio in pieno sole (per scatti a diaframma aperto) e per lunghe esposizioni, ed è davvero ottimo.

Ora mi è stato permesso di testare il filtro ND variabile della serie PRO di K&F, un filtro da ben 280 euro. Se lavorate già con i filtri, dovreste ovviamente utilizzare vetri di alta qualità su un obiettivo di alta qualità, ma un filtro per poco meno di 280 euro non è certo un'inezia e questo investimento dovrebbe essere ben ponderato. Quello che posso dire in ogni caso: Il filtro è il top non solo in termini di prezzo, ma anche di prestazioni e lavorazione.

Questo inizia già con la presentazione (confezione) di questo filtro, un sacchetto lavorato in modo pulito con coperchio magnetico, applicazioni in pelle scamosciata, fodera interna morbida e priva di pelucchi, una cinghia laterale con cui il filtro viene trasportato tirandolo verso l'alto.
Il filtro stesso è molto ben fatto e facile da usare con le due linguette in ottone.
Ha una resistenza molto buona durante la regolazione, non troppo pesante e non troppo leggera.
Il vetro non presenta difetti e anche le filettature sono assolutamente pulite.
Per quanto riguarda la qualità e le prestazioni dell'immagine, posso solo dire: TOP!
Non ci sono errori di colore, fusioni cromatiche o altri aspetti negativi. Posso anche lavorare con l'obiettivo a diaframma aperto in pieno sole e, se voglio, posso anche fare lunghe esposizioni con il diaframma leggermente chiuso con l'aiuto del filtro.
Come ho detto, la qualità dell'immagine è buona come se non avessi un filtro sull'obiettivo e così deve essere.
Le immagini che ho caricato (scatti di prova non impegnativi) sono state scattate con un'apertura di diaframma aperta e contro il sole.

La mia conclusione su questo filtro:
Lavorazione di altissima qualità / qualità dell'immagine impeccabile / sensazione eccellente. Prezzo molto alto
Ora ognuno deve decidere da solo se vale la pena considerare un tale investimento.

I already have a few filters at home, including the K&F Concept Nano-X ND Filter 77mm Variable Gray Filter ND2-32 for 75 euros, which I use on my wide-angle, for example in bright sunshine (for open aperture shots) and for long exposures and that is already really good.

Now I was allowed to test the variable ND filter from the PRO series of K&F, a filter for no less than 280 euros. Of course, if you already work with filters, you should also use high-quality glass on a high-quality lens, but a filter for just under 280 euros is not a pittance and this investment should be well considered. What I can say in any case: The filter is not only from the price level but also from the performance and workmanship at the top.

It starts with the presentation (packaging) of this filter, neatly processed bag with magnetic lid, suede applications, soft and lint-free lined inside, a lateral belt with which the filter is transported upwards by pulling.
The filter itself is extremely well made and with the two brass lugs it is easy to use.
It has a very nice resistance when adjusting, not too heavy and not too light.
The glass shows no flaws and the threads are also absolutely clean cut.
About the image quality / image performance I can only say: TOP!
There are no color errors/color cast or anything else negative here. So I can work with my lens in bright sunshine even with open aperture and if I like also with a slightly closed aperture with the help of the filter realize long exposures.
Image quality is as I said with me as good as if I had no filter at all on the lens and so it must be.
The pictures I uploaded (undemanding test shots) were taken with the aperture open and against the sun.

My conclusion on this filter:
Very high quality workmanship/image quality flawless/haptics excellent. Price very high
Now everyone must decide for themselves whether such an investment comes into question.

I've broken down my review for you and them into reason for purchase, first impression, product test, suggestions for improvement, tips and conclusion. I hope this helps with clarity.

I received the product free of charge as a Vine product tester, but this has no effect on my review. I also only test things that I can usefully use myself and integrate into my everyday life.

Reason for purchase:
I ordered this filter for 2 reasons. The first reason is that if I only want to travel with light luggage, I don't want to bring my entire plug-in filter system with me. The second is that I can use it well in videography, where I usually film according to the 180 degree rule. This means that in order to obtain a cinematic video image with a certain amount of motion blur in the individual frame, you film with a shutter speed of 1/fps x 2, for example, I film at 50fps, so I need an exposure time of 1/100s, which is not possible without an ND filter, especially in the wide angle range when the sun is shining.

First impression:
The packaging looks very classy, but she is also welcome to do that, given the price that is called for the filter. The filter is in an equally pretty and high-quality filter bag, which I have never seen in this form with round filters before. With the tab on the side, you can lift the filter to prevent accidental contact with the glass when removed. The closure of the bag is magnetic. A nice gimmick is that the cardboard packaging of the filter can be transformed into a small picture frame.

Product test:
The filter is a dream to the touch, heavy (91g) and easy to grip, I also really like the contrasting adjustment aids. These can also be removed if you want to continue using a lens hood. This requires a small microtorx, e.g. from a precision engineering kit. When the filter is adjusted, it is buttery smooth across all stages.

In the test, the filter shows no weaknesses. As a result, I could not detect any color cast and there was no X-Cross effect. The promised effect of up to 5 aperture levels is maintained. Technically perfect and that is the most important aspect of an ND filter.

Suggestions for improvement:
1. The sustainability aspect, as taken up when using cardboard as a picture frame, could also be reflected in the filter bag by avoiding the use of animal products (leather).
2. An 82mm variant would be desirable and recommended, then the filter could also be used on (m) a 24-70mm/2.8, for example.

Tips:
It is always advisable to buy such a filter in the largest possible diameter so that you can adapt it to as many lenses as possible in your own fleet using step-down rings. Of course, this also eliminates the option of continuing to use a sun visor.

Conclusion:
Technically perfect filter in the upmarket price segment.

I hope my review was helpful in your decision making

I've used ND filters from K&F in the past, so I wasn't surprised by the quality compared to newbies.

The filters allow sharp focus without any restrictions. Thanks to the really extremely thin glass and the thin frame, there is no cloudiness or dark spots at the edges. It is ideal that the filter has a thread mounted on the front, so that you can easily mount several of them one behind the other.

The frame has small brackets so that if you want to readjust it, you don't have fingers in the picture.

The ND Filter 67mm set is rounded off by a nice leather storage pouch. Overall, absolutely great!

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

The workmanship of the filter is really first-class. High-quality materials, excellent 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 you no longer have to rework.

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

Neutral density filters are an integral part of photography. They are used all the time, especially in landscape photography. You know these great pictures of flowing water that looks so “fluffy” soft — for something like that, for example, you need a neutral density filter.

A neutral density filter, or “ND filter” (neutral density filter), absorbs the light so that you can expose for longer. Because of this long exposure and the movement of the water, it looks so great.
Taking pictures with a neutral density filter darkens the incoming light and allows you to shoot better in very bright environments.
If you use a neutral density filter in bright environments, you can in return shoot with a wider aperture or longer shutter speeds.
You can achieve beautiful effects by taking pictures with a longer exposure time.
Pictures are usually overexposed if you choose a particularly long shutter speed.
With a neutral density filter, you can prevent this and take pictures with a long exposure time despite a lot of light.
As a result, movements become blurred and flow into one another.
For example, you can display water or clouds, as well as fast-moving objects, in a particularly creative way.

The K&F Concept Nano-X PRO series ND1000 filter impresses with excellent quality, it is delivered in a stylish case (magnetic closure). Includes a cleaning cloth.
I shot at the five pictures and numbered them. The difference is obvious.
The filter is worth the money, it is simply screwed on and even my lens protector still fits on it.
This filter makes you want more and gets full points from me!