The magnetic adapter ring is a plus. You can even stack it with the ND filter. The case is also very durable and should be great for protecting my filter when tucked into my camera bag.

Overall I am very impressed with this filter. It's so satisfying how the filter snaps into place. This filter will definitely be a staple in my everyday camera accessories and I would recommend this to any amateur or professional photographer/videographer.

This ND filter was developed specifically for the iPhone. This should be taken into account, otherwise the verdict will probably not be so favorable. The special thing about it is that this ND filter with its filter ring completely encloses the camera module of the newer iPhones. The actual filter then lies directly on the lenses and sits really well.

Unfortunately, this doesn't work with a cell phone case that has a camera protector. Then the camera module becomes too big and the filter no longer fits over it.

The whole thing is held in place with a fairly tight clamp, which of course then covers part of the display. But in my opinion that's not particularly important.

The filter can be adjusted from filter strength ND2 to ND400 by simply turning it. The whole thing is done with a quarter turn, so all levels are pretty close together, so you should turn slowly. There is a 10-level division on the ring, but it can still be adjusted continuously. The filter does not always have the same effect on all three lenses. With the ultra-wide angle of the iPhone 14pro, for example, you can get the filter ring in the picture with some settings. In some settings you notice a slightly stronger vignetting. You have to try it out a bit, but you can get the hang of it quickly.

Who needs something like that? Certainly no one who doesn't know straight away what an ND filter does. The product is aimed more at photographers who want to get even more out of the iPhone and, especially in bright light, still want to use long shutter speeds. To do this, you would have to delve a little deeper into the subject. There are numerous, very good YouTube videos on the subject...

I think it's really great that the filter holder or clamp with a 52mm thread can also accommodate other filters. A polarizing filter or graduated filter would be exciting here for different effects.

In any case, I am very happy with this ND filter, even if I probably won't use it that often. I tend to take the photos or videos that can be produced with it with a system camera. But if you're travelling light or want to experiment with iPhone photography, this is the right choice. The price is unbeatable for this great quality.

This is an inexpensive Chinese-made filter that has a good standard of manufacture and a decent coating. I'm not going to waste your time telling you what a polarizing filter does - if you're here looking for one, you already know! What I will say is that if you don't already own one, it's a very useful addition to your kit, especially if you're shooting outdoors or shooting reflective surfaces. POSITIVES * Good optics * Coated * Inexpensive * Comes with case NEGATIVES * Adjustment is made difficult by the extremely thin ring * Rotation is a little stiffer than I like * Filter case is huge - too big for a gadget bag and doesn't close securely. The optics are better than many I've owned in this price range, so no complaints. This is an ultra-thin filter, which helps avoid the risk of vignetting. The downside is that this makes ring adjustment tricky, especially with the slightly stiff rotation. With the lead rotating, the filter can come loose unless it's screwed on very tightly, making re-triggering a pain. Also, the front thread is so short that you can only use the supplied lens cap rather than the better one that came with your lens. Vignetting is only really a risk with ultra-wide lenses, and with medium to long lenses I personally prefer a deeper filter ring to allow for easier adjustment and the use of my original lens cap. It comes with a free lens cloth and lanyard, but I'd rather the money was spent on a better case. I consider this a budget filter for wide angle lenses. It doesn't have the same quality or technical capabilities as my Lee polarizing filter, but that's in a whole different price and performance bracket. You usually get what you pay for in photography, and at this lower end of the spectrum, the price/performance ratio of the K&F Concept version is solid and offers good value for money. I give it a solid four stars. One person found this information helpful

I like this camera it comes with a case.

I’ve never used a variable ND filter, so this was really cool to be able to test out. It came in a protective plastic hard case along with three microfiber cleaning cloths. While slightly heavier than normal nano filters, I still was surprised at how lightweight it was comparatively.
Adjusting the strength of the ND was smooth as butter. The ring glides with minimal effort to achieve a lighter or darker filter between the min and max settings. If you keep twisting it past these points, it goes through the same grading scale until it reaches the starting point again. The threading is well made, so installing it on my lens was easy.
After some testing, I haven’t seen any vignetting or loss in sharpness. There is only minimal color shifting, and I didn’t notice any until around the ND1000 mark.
The image quality is fantastic with this, but the really beauty of it is the convenience. While it doesn’t take a long time to change a filter, it becomes annoying quick having to switch multiple times. It also takes up precious space in your kit when you are trying to travel light. With this, there is no more fumbling with multiple filters trying to get the right combo for the shot. If I need to adjust, I just give the ring a quick twist and I’m good to go. And instead of a case with multiple filters taking up space, I have one filter that does the job of a whole set. It’s absolutely fantastic. Nice job K&F!

I had been hesitating between several brands for a while to choose a filter holder for ND and GND filters. I took advantage of a flash sale to acquire this kit. I am not disappointed.
the set seems robust and easy to store.
The case, quite pretty, has 5 compartments, 3 of which, for square ND filters, can be lifted by means of a ribbon. On the back of the case, there is a ring to pass a strap and a passage for a belt. I would have liked a slightly more spacious compartment to house the adapter rings with the CPL filter when it is disassembled.
The assembly (or disassembly) of the elements is well explained in a manual in several languages, including French.

Main positives:
No color cast or loss of sharpness on the first tests carried out.
The plastic frame with its tabs to handle the ND filters.
The CPL filter installation system on the filter holder.
the knurled knob for mounting the adapter ring and the rotating block of the filter holder.
The very accessible wheel to control the polarizing filter.
Firm hold of the square filter on the filter holder.
The robustness of the metal filter holder.

If you have to find some negative points:
The slightly too vigorous maintenance of the square filter in the filter holder.
the click too hard to lock the CPL filter in the filter holder.
No pouch to independently protect the CPL filter in the case.
No CPL protective cover when the assembly is installed on the lens.

It's been a while since I hesitated between several brands to choose a filter holder for ND and GND filters. I took advantage of a flash sale to purchase this kit. I'm not disappointed. The whole thing seems sturdy and easy to store. The case, quite pretty, has 5 compartments, 3 of which, for square ND filters, can be lifted using a ribbon. On the back of the case, there is a ring for passing a strap and a belt loop. I would have liked a slightly more spacious compartment to accommodate the adapter rings with the CPL filter when it is disassembled. The assembly (or disassembly) of the elements is well explained in instructions in several languages, including French. Main positive points: No color cast, nor loss of sharpness on the first tests carried out. The plastic frame with its tabs for handling the ND filters. The system for placing the CPL filter on the filter holder. The knurled button for mounting the adapter ring and rotating the filter holder. The very accessible wheel to control the polarizing filter. The vigorous holding of the square filter on the filter holder. The robustness of the metal filter holder. If we have to find some slightly negative points: Holding the square filter a little too vigorously in the filter holder. The click too strong to lock the CPL filter in the filter holder. No pouch to independently protect the CPL filter in the case.No protective cover for the CPL when the assembly is installed on the lens.

You can get an adapter ring for just under €5, in my case from 58mm to 77mm. This is made of metal, can be easily screwed onto the lens and the larger filters can also be easily attached. So I give it full marks here.