I am a passionate landscape photographer as a hobby and have now switched from the screw filters to this rectangular filter system from K&F. The screw-in filters were all fine, but you don't have the option of attaching a graduated filter to the ND filter in order to achieve even nicer effects.
It is mounted on the lens using so-called adapter rings, which are included in the most common sizes for lenses.
After attaching the adapter ring to the lens, the filter holder is attached. This is secured by a small lever (spring-loaded) and later released again with this.
Now you can slide the filter plates into the filter holder. This lifts a bit severely but it should also hold and must not wobble.
It is also important to observe that the filter used is close to the lens so that no more light can penetrate between the filter and the lens, which could possibly ruin the recordings.
In terms of quality, the system makes a good impression considering the price. The only thing I noticed negatively is that the filter holder has some play after it is placed on the adapter ring and why there is no adapter ring for a 55mm filter diameter in the set, I also ask. 55mm is a common diameter for lenses.

I can highly recommend the K&F system for amateur photographers. The professionals will probably use filter holder systems from other manufacturers, but they also cost a lot more.

The adapter rings allow us to place the filter holder on any lens, as we have a large number of different diameters. They are made of black metal and well finished. With labeling on each ring with the corresponding diameter.The filter holder is metallic with the part where the filters go from a kind of hard plastic. Two 100x100 filters fit and 100x150mm gradients without any problems. The attachment system to the adapter ring is via a very manageable metal tab.In several tests I did under different lighting conditions, I did not notice the entry of residual light through the space between the filter and the filter holder. The photos have a slight magenta tint that is very easy to correct when editing, but it is not at all overdone. I am very pleased and enjoy it very much. I recommend it!

am a passionate landscape photographer as a hobby and have now switched from the screw filters to this rectangular filter system from K&F. The screw filters were all fine, but you don't have the option of attaching a graduated filter to the ND filter in order to achieve even nicer effects. It is mounted on the lens using so-called adapter rings, which are included in the most common sizes for lenses. After attaching the adapter ring to the lens, the filter holder is attached. This is secured by a small lever (spring-loaded) and later released again with this. Now you can slide the filter plates into the filter holder. This lifts a bit severely but it should also hold and must not wobble. It is also important to observe that the filter used is close to the lens so that no more light can penetrate between the filter and the lens, which could possibly ruin the recordings. In terms of quality, the system makes a good impression considering the price. The only thing I noticed negatively is that the filter holder has some play after it is placed on the adapter ring and why there is no adapter ring for a 55mm filter diameter in the set, I also ask. 55mm is a common diameter for lenses. I can highly recommend the K&F system for amateur photographers. The professionals will probably use filter holder systems from other manufacturers, but they also cost a lot more.

It's a well-made adapter that works perfectly, both on the lens mount and on the camera. The only negative is the ring, which locks and releases the exposure, allowing the rotation to rotate with minimal force applied, causing the ring to rotate unintentionally. There should be more resistance. Besides, quality and price are good product.

bought the adapter because I also want to use my existing Nikon lenses on the new BMPCC4K. Since the vast majority of lenses have an aperture lever, they can also be used although they do not have a separate aperture ring (lenses without an E-mark!). The adapter makes a very valuable impression. It is made of metal and feels good in the hand. It easily connects to the camera and lens. I haven't found any game so far. If this occurs during use and possibly leads to scattered light, I will provide an update. The adapter is delivered in a small plastic box. This makes it easy to store or transport when not in use. The silver ring is used to set the aperture. However, there are no numbers, only a symbol for an open and one for a closed aperture. But you can see directly on the display how turning the ring affects the brightness. So I don't miss numbers. In addition, I have read on other adapters with numbers on the ring that these values are not as finely graded as the numbers make it seem. I am very happy with this adapter. Of course, you lose light intensity because every assembly between the lens and the sensor "swallows" light. But this adapter only costs a fraction of what a Speed Booster costs. Also, you can't get a speed booster with contacts for Nikon lenses. No information is passed on to the camera, so you have to set everything manually even when using a speed booster. I can highly recommend this adapter to anyone who can get along with a somewhat lower light intensity.

have an EOS 350D available on which I want to test the use of my Nikkor AI lenses. I received the adapter ring today and tried it out right away. The processing of the adapter ring is very good, the connection to the camera works perfectly. Since there is no description, you first have to think about the correct attachment to the lens (description below). When this is done, the ring can be put on and fastened (relatively stiff). Detaching the ring from the lens is also relatively difficult, not at all for me at first until I found the right procedure and "practiced". A point is deducted for the missing description. All in all, a recommendable adapter. It remains to be seen whether the problems identified so far with the EOS can be solved with connected AI lenses. Description of connection/dismantling of the adapter lens: Set the maximum f-number on the lens. Position the adapter with its red dot opposite the black dot on the lens. Fasten anti-clockwise (movable pin of the adapter goes into the U-groove of the bayonet ring). This also ensures that the lens is correctly aligned when the adapter is connected to the camera (aperture and distance settings visible from above). To disassemble the adapter, hold the aperture ring with one hand and use the index finger of the other hand to press down on the small release lever while turning the other fingers clockwise to release the adapter from the lens.

The lens is securely attached to the adapter ring and this is precisely and stably inserted into the camera body. The Nikon Nikkor lens is on a Nikon Z camera. The adapter is well made and has an opaque interior to prevent reflections. I'm giving it 3 stars for value for money, not because it's obviously bad, but because it costs more than other mount/camera body combos. The whole thing deserves 5 stars because it works very well.

had bought a Fuji X-T10 mirrorless camera and was waiting for a Fuji lens to arrive so I could use it. I had a Nikon 35mm g at home and I was thinking about using it on my Fuji while waiting for the proprietary lens. After careful research I have ordered this wonderful adapter which I will try to describe below. It arrived in a small cardboard box wrapped in shockproof plastic. The adapter is made of excellent material, it is made entirely of metal and is pleasing to the eye. It can be installed easily and quickly on both sides. It has a metal ring that is used to close and open the membrane. That last feature deserves an explanation: the adapter has no electrical contacts, so any lens you mount will lose autofocus. If you mount a lens that is equipped with an aperture ring, you can use it without any problems because the adapter does not interfere with this ring. On the other hand, if you mount a lens without an aperture ring, as in my case, you can have trouble selecting the apertures that the mirrorless camera actually no longer shows on the display. However, this adapter features a ring for minimal control of the diaphragms. To get the best out of it, before mounting the lens, make sure the adapter ring is fully closed (smaller ball), then mount the lens. Then mount the adapter on the camera. In the case of the XT-10, I had to select non-lens speech noise from the settings menu and that was it. Despite the lack of autofocus and minimal control over the apertures, I took wonderful photos. Highly recommended for those who are already experts at manual focusing.