First time using an ND filter let alone a 2-in-1 filter, very easy to use, much cheaper than other brands, so far so good

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.

In addition to square filters, I have now also bought the inexpensive magnetic filter holder set. I can only say: topp. However, I lack the possibility of obtaining ND 8 and ND 64 (magnetic), because only ND 1000 and polarizing filters are available. A second glass-filled filter holder is included, which is super with adapter ring for a second lens size can be kept permanently and still! fits in the super handy case. For now, this inexpensive set with magnetic holder is enough for me; if I have further requirements, I will probably switch to the "large" filter holder system from another manufacturer (approx. 400 euros with three ND filters). Which photographer does not know this "want to have?". In short, the post on YT by Riko Best has convinced me. Would I recommend it? Yes, to anyone who wants to work with gray filters now and then. LG

I had never owned a K&F Concept brand filter before and was pleasantly surprised when I first used it in my landscape photography. The reverse graduated ND filters from the popular brands of photographic filters tend to be quite expensive, and this one in particular is less expensive and produces results equal to and even better than those of the most reputable filter brands. It is made of glass, which is an advantage over resin filters because it does not scratch as easily. I really liked the filter cover, which is made of leather with interior protection. In short, I liked this filter very much and I am sure that I will use it very often in my landscape photography.

In addition to square filters, I also bought the low-cost magnetic filter holder set. I can only say top. However, I lack the possibility of obtaining ND 8 and ND 64 (magnetic) because only ND 1000 and polarization filters are available. A second glass-filled filter holder is included, which is super durable with adapter ring for a second lens size and yet! fits into the super handy case. For the time being, this low-priced set with magnetic holder is enough for me; for further demands, I will probably switch to another manufacturer's “large” filter holder system (about 400 euros with three ND filters). Which photographer doesn't know this “want to have?” In short: Riko Best's contribution to YT convinced me. Would I recommend it? Yes, anyone who wants to work with grey filters now and then. LG

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.

These are so easy to use and the quality is fantastic - both the build quality and the picture quality. I can't see any colour cast whatsoever from both the CPL & ND filter. I think you would really need to pixel peep to see any sharpness difference, and even then I'm not sure there is.
Being able to attach the filters to both the UV filter and filter ring is really clever - I keep the UV on my 24-70 F4 and the filter thread ring on 16-35 F4 so it makes it even faster to clip on the filters no matter what lens I use.
Since the ND isn't variable, there's no dark X. And no vignetting at 16mm, unlike when I use my square filter set.

The downsides that I see at the moment:
- The range of NDs isn't as big as a square filter system (yet) and again I'm not sure if you can buy them as singles or whether it's just part of these kits

In addition to the square filters, I also bought the inexpensive magnetic filter holder set. All I can say is: great. However, I don't have the option of purchasing ND 8 and ND 64 (magnetic) because only ND 1000 and polarizing filters are available. A second glass-filled filter holder is included, which can be stored permanently with an adapter ring for a second lens size and still! fits into the super handy case. For now, this inexpensive set with a magnetic holder is enough for me; If I have further requirements, I will probably switch to the "large" filter holder system from another manufacturer (approx. 400 euros with three ND filters). Which photographer doesn't know this "want to have?" In short: Riko Best's post on YT convinced me. Would I recommend it? Yes, anyone who wants to work with a gray filter every now and then. LG