All in all a good product. The quality seems good! Everything is made of metal and makes a robust impression. The adapter rings only have a thread, which I can screw onto my lens (in my case 49mm). If I want to mount a polarizing filter, etc., I first have to put the screw filter and then the adapter on top of it. What I also noticed is that the adapter ring sits very smoothly in the filter holder. It's almost like a steering wheel which you can easily turn several laps. A small rubber lip (on the adapter or on the holder) would possibly be a good product here!

I had never owned a K&F Concept filter before and was pleasantly surprised when I first used it in my landscape photography. The reverse graded ND filters of the popular brands of photo filters tend to be quite expensive and this one in particular is more affordable and achieves results that match and even better than the most reputable filter brands. It's made of glass, which is an advantage over resin filters as it doesn't scratch easily. I really liked the filter cover, which is made of leather with inner protection. In short, I really liked this filter and I am sure that I will use it very often in my landscape shots.

When you open the incoming package, you will find that the packaging is very high quality. The brand is very careful in presenting their products and the materials are of high quality. The filter holder and adapter ring are metal and the filter holder has a spongy area whose function is to seal with the filter without letting light through. Once the filter holder is attached, it is easy to move. crtsal 100x100 quality is very good, with highly polished edges. The filter holder has two slots for square filters, but the advantage is that the ring screwed on the lens can be screwed with another round filter, for example a polarizing filter. I think the picture is very good. As with the brand's round filter, the sharpness is not lost, the color cast did not catch my eye, anything that can be edited during development is appreciated. The ND1000 filter included in the kit enables long exposures in strong light. The sample photos are photos taken on a cloudy afternoon with and without a filter. Those with filters were made with an exposure time of 20 seconds.

Scope of delivery:

- filter holder for 100mm x 100mm filter
- adapter ring 67mm
- adapter ring 72mm
- adapter ring 77mm
- adapter ring 82mm
- padded cardboard box for filter holder

The set makes a very valuable impression overall.
The adapter rings are made of black anodized aluminum - they are well made, not sharp-edged and the thread can be easily screwed onto lenses.
Apart from the filter inserts, which are made of plastic, the filter holder is also made of black anodized aluminum. Here, too, the processing is excellent. Maybe the quality of the plastic inserts could be a tick better, but that's already whining at the highest level. The inserts fit all 100mm x 100mm filters with a thickness of 1mm - 2mm.
packaging was impeccable; Adapters are individually wrapped; Filter holder is in a nice padded cardboard box.
Full points and recommendation for a perfect rectangular filter system at a significantly lower price than some other manufacturers.

The filter does what it is supposed to do, it extends the exposure time. I haven't noticed any vignetting or wrong color reproduction so far. And so I'm satisfied. The packaging of the filters is very good and practical, some higher-priced filters can't do that so well.

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 are well made. Labeled on each ring with the appropriate diameter. The filter holder is metallic with the part where the filters go made of some sort of hard plastic. Two 100x100 filters and 100x150mm gradients fit easily. The system of attachment to the adapter ring is via a very manageable metal tab. In several tests that I carried out 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 which is very easy to correct when editing, but it's not exaggerated at all. I am very happy and enjoying it very much. I recommend it!

After looking at the competitors and trying brand names she found these at a fraction of the price without compromising on quality. The overall user experience from delivery is exceptional. You are very much buying a high end product without the overpriced name brand. I bought these to help with my landscape photography and they work exceptionally well with my Sony A7III. The camera practically sees at night so to get a long exposure without this filter was incredibly difficult, I would often have a very split image with the moon/sun being very bright at the top and everything under the sky being in total darkness. After using the occlusion filter, all additional adjustments were done on the fly. The material feels very sturdy although I don't plan to test the limits, I believe it's scratch resistant. Looking forward to sunsets to test this further.

I received the new X-PRO filter set today and have already tested its applicability in the apartment. I'll give you a verdict on the quality of the filter glasses and how they can be combined in one shot... The box supplied holds the holder + adapter rings + CPL + ND 8/64/1000. You can pull out the compartments on the drawstring and then remove the filters very easily. The plastic filter frames are discreetly sharp-edged, but not uncomfortable, and allow the filter to be removed and handled without having to touch the glass. Thanks to the tabs on the frame, the filters can also be pulled out of the holder very easily, especially in any order. I ordered two empty frames in 100 X 150 from the manufacturer's website, which should hold my graduated filters after receipt, that I have from another manufacturer. I'm curious how well this works. If it works, then I have a complete system for myself, with CPL, three ND filters and two graduated filters (Soft 0.9 and Reverse Soft 0.9). Sliding the filters in and out of the holder requires some force, but isn't awkward or imprecise. In this way, the graduated filter will also be easy to align. The handling of the CPL filter with the insert bracket is great, the turning mechanism is a bit rough, but precise. Screwing the adapter rings onto the lens works very well, the threads are cleanly worked, so nothing rubs. Attaching the holder to the adapter ring is also a joy and the presence of a set screw is very welcome as the holder rotates on the ring with relative ease. The handling of the system has already convinced me, I can live well with "only" two slots for my needs and I'm looking forward to the first use, in the next few days, in the great outdoors and with cold fingers. So far I've worked with round screw filters and dispensed with gradient filters, which I would like to change now. I also looked at the system from Rollei (Mark II), which cannot keep up with the handling of the X-PRO from K+F. Everything is very flat and fiddly, offers hardly any contact surface for holding and assembling the parts. Getting the polarizing filter or adapter ring out of the holder is no fun and almost impossible with cold fingers. K&F solved this much better. If you want to use gradient filters, the X-PRO Set is a good choice, if you only need gray filters,

I loved the quality of the materials, all metallic. I looked at many kits but they were all plastic and this one in particular caught my attention from the comments. The truth is that it was a success because any other similar kit does not fall below 300€.The nd1000 optical filter is made of glass and gives a very good quality. The only thing I noticed is that it loses a bit of saturation and the white balance is a little bluish, but when processing the RAW it's easily remedied. You increase the color temperature and saturation and you're done!! (I use a Canon 80d + 16-35 f4's). I imagine each optic will be different. Attached some photos so you can see the difference with filter and without filter. Exposure time on the photo with the 30" filter. If you want to start in the world of filters, for this price don't even think about it. Excellent results.

All in all a good product. The quality of the glass filter (ND1000) looks good and can also be easily pushed into the holder. Everything is made of metal and makes a robust impression.