really like the convenience of this magnetic filter system. All you have to do is thread onto the base ring and magnets do the rest. Makes it less likely to damage your lens' threads if you don't have to put on and remove a filter every time you need to use it. I use this with a full frame 24-105mm lens and the base ring works with the lens cap and hood, although you'll probably have to remove the hood to snap the filter or your fingers will get in the way. Each of the filters themselves are slightly heavier than the bolt on K&F versions, probably because they have to make the filter ring out of a magnetic steel instead of aluminium. Whatever the reason, they feel a lot more premium than the regular K&F version. In terms of performance, it's a bit of a mixed bag. I don't have tremendous experience with CPL and ND filters (this is my first set) so I don't know what would be considered good performance in a given price range. Let's start with the ND: it seems close if not a full 10 stops, which is great; the previous K&F screw 10 stop ND which I returned with only about 8 stops in practice. The ND has a noticeable color cast (see: in-camera photos of the sea). The ND image that brought the raw files into Lightroom had 26 more dots of magenta tint and was 1000K warmer than the unfiltered image. This cast was relatively easy to correct, although the colors weren't exactly the same. Less correctable was the 24mm vignette, which needs to be cropped out. With my lens at least, a quick crop test indicated I lose about 1mm of focal length to the vignette. Note that because the filter is magnetic, there is a small amount of float between the filter and the lens, so the vignette is not always symmetrical or consistent from use to next. In aggregate, the CPL filter (photos looking out the window) has a similar vignette to the ND filter at 24mm, but seems to reduce some reflections in my windows. Not much for me to point out ours here, it seems to do the job. The set comes with a UV filter, but I don't plan on using it unless I'm in a rainy/dusty environment where my lens needs a bit more protection, so I haven't tested it yet. For both the ND and CPL filters, I didn't notice any noticeable decrease in sharpness caused by using the filters. However, due to the burst of color with the ND filter, I recommend either shooting in RAW or setting your white balance before putting on the filter. For the price ($110), I think the performance of these filters is acceptable. I'm a little disappointed with the vignette, but I've heard of much more expensive filters that have similar issues, so I don't want to be too harsh on this set. All in all, for someone like me who does this for fun, I think it's a great system to learn the basics until I can justify upgrading to something premium. If you're a pro and making money from your photos, then maybe look into something more upscale like K&F Concept, or invest the time to create a preset to fix the color cast.

Full disclosure: I received this filter system at a significantly reduced cost in return for my unbiased review.

I just purchased a new Canon RF 100-400 lens that has pretty good glass but is not L quality. Although I have a good black and white CPL filter that matches this lens, I have never been very happy with the color cast. I have tried other K&F Concept lenses and was very impressed with the neutral color cast. So I decided to give this polarizer kit a try.

I really like the technology in this kit. This kit comes as a compact sandwich with machined metal caps front and back. All caps and filters are clearly marked with the filter size. There is a small storage bag to protect the filters and your other stuff when you throw them in your bag.

I previously tried another K & F filter and while I was very impressed with the glass, I was much less impressed with the machined aluminum frame. Unlike the previous filters, these attach easily to my lenses and don't bind. In practice, the knurling on the filters makes removal very easy and in the case of the CPL, the adjustment is very smooth. There is noticeable resistance, but no hint of binding or freedom of movement that you get with cheaper filters. The feel of this filter is quite nice.

The thin profile UV filter is MRC coated to reduce glare and improve cleaning. This filter produces virtually no color cast at all. When held up to a white background, I can't tell the difference between filtered and unfiltered white. I don't usually use UV filters because most of my lenses have better front elements than any filter I own, but with the RF100-400, I'll probably leave the UV filter on the lens since it doesn't have the same quality coatings as my other lenses.

The CPL is fairly thick, but not so thick that I will worry about vignetting since I use these mostly with medium to long telephoto lenses. All CPLs affect color to some degree. Depending on the polarization and angle of the sun, they usually darken the sky and change the color of the water, sometimes dramatically, so with a CPL it is difficult to determine what color cast may be present. Using the same test on a white background, I can see a slight cast against the adjacent white background that seems to have a somewhat brownish cast, but could simply be the result of light loss from the CPL. In test photos, I could not see any perceptible cast at all. It's close enough to neutral that I don't think it will have much effect on color correction in post.

All in all, really nice filters and pretty good value for the money. Recommended.

This is a mid-to-high-end filter that's perfect for getting started with using filters. For the price it has, it goes without saying that it has color dominants, but much less than those of gelatin. It will look blue or green depending on the balance you have in camera, but that's easily corrected in editing or in the camera itself. For a photography enthusiast like me, this is a more than acceptable result.

First off, I'm a fan of K&F's products, I try to use them as much as I can during photo sessions, since they just give good consistent results.

However, the ONE complaint I've always had, is that K&F's product line was quite limited to low to mid range products. Don't get me wrong, they are amazing for what they are.. and I LOVE having them on location. But, as with any product I use in the field, they're often NOT the same products I will used in a fully controlled environment. In a perfect world, I would be able to take all of my studio gear on location, and not have to worry about potential damage to my gear.

To that end, K&F's mid-range type of filters and equipment have worked extremely well..

However.. I've always wondered.. what if my preferred manufacturers actually produced higher end gear.. would the results be as good? Better? What might I be missing, by taking certain types of gear, over others?

When I saw that K&F was producing a 'Nano' sort of lineup, a while ago, I was excited.. but also somewhat concerned... I already had my high end filters that I would use on special occasions, and for studio work... would K&F be able to actually meet that quality? If so.. could I stop buying gear from manufacturers that I didn't want to use, due to their awful customer support practices?

When I saw this filter pop up on my recommended feed.. my curiosity got the better of me, and I had to order it.

I grabbed the 82mm version, since my primary workhorse lenses are 82mm. Sigma 24-70mm f/2.8 DG DN Art, is commonly my 'Go To', though having rented and used a Tamron 35-150mm f/2-2.8 Di III, a few times, now.. and having it on my wish list.. both use 82mm filters.

After using it for a couple of sessions, now... both studio and on location, I have some initial short term thoughts:

Exposure change is minimal. - This is a big deal, since so many 'cost effective' polarizers will often drastically impact exposure. I've seen some filter change the EV by as much as a full stop. At that point, a CPL is operating more like a slight ND filter, and is not really optimal if all you're wanting is glare reduction. This one, I would say reduced the EV by roughly 1/8th of a stop when installed.

Color shift also seems to be minimal, if there is any at all - CPLs are also often plagued with the problem of changing the color of a scene, when they're applied, and in the case of variable polarizers, you may even experience a color shift while adjusting the amount of filtering being applied. This isn't ideal, as it just means you're going to have to do more color adjustment in post. Now, that said, keep in mind, the way a variable CPL works, if that if you reduce the glare from a source that is producing a color cast, you WILL have some color shift. This is just the nature of light.. similar to using a gold colored reflector for a subject illumination. If you remove the gold color from the reflector, there WILL be a color change. This is not the same as a filter created color shift.

Distortion seems to be non-existent - This is ANOTHER problem that so many filters (in general) have, and can often be so slight, as to not be seen until you're working with your files (RAW or otherwise) in post. I've seen a large number of filters absolutely ruin photos in the past, so it's something I tend to be VERY twitchy about. This filter seems to have no distortion at all. I'm EXTREMELY happy for that.

Quality & build - This filter has 2 parts to it. When I say that, I don't mean there's 2 physical parts that you have to attach... just that there is the static mount, that attaches to the end of the lens, and the adjustable portion that floats and rotates on the end. The static mount is actually a bit on the small side, which means if you are going to be attaching this to your lens, with any bit of snugness, you may want to use a filter tool for it.

NOTE: This filter does NOT have a forward facing threaded mount. If you use a lens hood that attached via the filter threads, it WILL NOT WORK with this filter. Additionally, the lack of a forward thread also means you cannot stack this filter with others, OR you will want to use it as your last filter in the stack. I know.. there is some photographer out there, right now, reading this, who is screaming that you shouldn't stack filters, ever.. but you saying that, doesn't change the fact that there ARE those that do. If you DO still want to use the CPL as a middle filter, you're going to need to get some external mount adapters to do so.

Case - The case the filter comes in, is actually a nice little leather and denim case, with a pull string on the side, that will push the filter out for you. My only gripe with this case, as with so many others, is that it'd be nice if the case had a small insert for a label. When carrying around a kit of filters, and you're operating in lower light conditions, it's often a pain to read the edges of the filters to determine which one you're grabbing. Adding a small label pouch would be an awesome addition.

Un-important - The packaging of the filter is quite nice, having a sturdy foam framed box, and including a microfiber cloth is a nice touch. The fact that the box turns into a 'picture frame' is gimmicky, and borderline insulting, as if the average person buying this were a child, who may become super excited over using a dense foam-board package as a photo frame. It's a $180 lens filter... the person buying this isn't going to spend that, and then not buy a decent frame for any photos they produce. This sort of marketing gimmick might work for those individuals buying a $20 CPL for their instagram photos.. but this filter is clearly aimed at the higher end photographer.

So.. that brings us to the big question.. how are the results? Honestly, I can't find a reason to complain at all. Colors come through as expected, no distortion, and absolutely no image reduction. The smaller mount point on the front lens element keeps flaring down to a minimal, and produces nice, crisp fantastic images.

The variable polarization works as expected, but I would have liked to see it spread a bit more evenly around the lens. Right now, when I turn the adjustment ring, there seems to be an awful lot of lack of polarization for a good amount of the filter, before the polarization kicks in, quickly.. a more gradual approach would have been preferred, BUT, that's nothing different from the current high end CPL I'd been using, either.

Which brings me to the price... at the currently listed price of $180, this filter is squarely in the upper end pricing for a CPL, which is an area that is already a rough spot to be in, since CPLs usually start to lose their price to performance around the $100-150 range. The $180 range now places you clearly in the range of B+W, Zeiss, and Hoya... 3 of the big names that dominate that market spot. It DOES perform on par to may of those products, but then again, you also have companies like PolarPro that have been making leaps and bound in that area, too, with the latter being VERY aggressive in their price to performance. I've had experience with all of the above, and while I really like K&F's customer service, and the fact that they're a LITTLE cheaper than many of the aforementioned brands, it doesn't change the fact that they MIGHT be pricing themselves out of the competition. If this filter was aimed at a lower price point, say $130-150, it might be an easier pill to swallow, especially if you're the type that wants a separate filter for every lens in your kit (as opposed to using a step down/up filter set).

That said, so far I'm immensely happy with the results I'm seeing with this CPL, and I'm cautiously optimistic that my long term experience will keep me comfortable with this CPL... time will tell, but for now, I'm cautiously recommending it, even at its current price.

I have the K&F magnet system on all my lenses and, in addition to the Black Mist, I have several of the appropriate ND and CPL filters here. They're so handy, easily stackable and the connection is strong enough that I don't have to worry about one of them falling off. The black fog effect is very low here and is only really noticeable with a lot of backlighting. Many cheaper filters often have a color cast, but I didn't notice that at all with the K&F.

The only downside is that with my Sony lenses, at least the included magnetic caps are really hard to pull off when you have the lens hood on the lens (either forwards or backwards). A grippy element on the front of the cap would have helped. I could 3D print a holder and glue it there to fix it. As the caps aren't really the main reason for using a magnetic filter system although I still give 5 stars they would have been a nice bonus if they worked well but they aren't really critical to the product.

I really like the convenience of this magnetic filter system. You only need to thread on the base ring and magnets do the rest. Makes it less likely to damage the threads of your lens if you don't have to keep putting on and removing a filter on every time you need to use it. I am using this with a 24-105mm full-frame lens and the base ring works with the lens cap and the hood although you probably need to remove the hood to snap on the filter because otherwise your fingers get in the way.Each of the filters themselves are quite a bit heavier than the screw on K&F versions, probably because they need to make the filter ring out of a magnetic steel instead of aluminum. Whatever the reason, they feel a lot more premium than the regular K&F version.In terms of performance, its a bit of a mixed bag. I don't have tremendous experience using CPL and ND filters (this is my first set) so I don't know what's considered good performance at a given price range. Lets start with the ND: It seems to be close to if not a full 10-stops which is great; the previous K&F screw-on 10-stop ND which I returned clocked in at only around 8-stops in practice. The ND does have a noticeable color cast (see: photos of the sea right out of camera). Bringing the raw files into Lightroom, the ND image had 26 more points of magenta tint and was 1000K warmer than the no-filter image. This cast was reasonably easy to correct although the colors weren't exactly the same. Less correctible was the vignette at 24mm which needs to be cropped out. At least on my lens, a quick crop test indicated at I was loosing about 1 mm of focal length to the vignette. Note that since the filter is magnetic, there is a small amount of float between the filter and the lens so the vignette may not always be symmetric or consistent from one use to the next.Moving on, the CPL filter (photos looking out the window) has similar vignette to the ND filter at 24mm but appears to cut down quite a bit of reflections in my windows. Not much for me to point our here, it seems to do the job.The set does come with a UV filter but I do not intend to use it unless I am in a rainy/dusty environment where my lens needs a bit more protection so I haven't tested it out yet.For both the ND and the CPL filter, I did not detect any noticeable decrease in sharpness caused by using the filters. However due to the color cast with the ND filter, I suggest either shooting in RAW or setting your white balance before putting the filter on.For the price ($110) I think the performance of these filters is acceptable. I am a little disappointed with the vignette but I have heard of much more expensive filters having similar issues so I don't want to be too hard on this set. All in all, for someone like me who does this for fun, I think its a great system to learn the basics until I can justify the move to something more premium. If you're a professional and make money off your photos, then maybe look at something more upmarket like Freewell or invest the time creating a preset to fix the color cast.

I have the K&F magnet system on all my lenses and, in addition to the Black Mist, I have several of the appropriate ND and CPL filters here. They're so handy, easily stackable and the connection is strong enough that I don't have to worry about one of them falling off. The black fog effect is very small here and is only really noticeable with a lot of backlighting. Many cheaper filters often have a color cast, but I didn't notice that at all with the K&F.

The only downside is that with my Sony lenses, at least the included magnetic caps are really hard to pull off when you have the lens hood on the lens (either forwards or backwards). A grippy element on the front of the cap would have helped. I could 3D print a holder and glue it there to fix it. As the caps aren't really the main reason for using a magnetic filter system although I still give 5 stars they would have been a nice bonus if they worked well but they aren't really critical to the product.

I tested the K&F Concept Nano-X PRO series ND1000 67mm neutral density filter with the Sony A7RII on a Sony SEL-20F18G.

The design of the K & F is a slim filter. This can prevent vignetting in an extremely wide angle, but the slim frame makes handling difficult when screwing and screwing on. More, as easy to handle, I would not turn on the filter. In any case, it should be positively mentioned that the filter has a threaded socket at the front, so that several filters can be screwed one behind the other. In theory, you could also use several neutral density filters in series. Depending on the type, the lens hood and lens cap can also be fitted. The filter comes in a high-quality, sturdy bag with magnetic closure. As a little gimmick, the manufacturer also includes a microfiber cloth for cleaning.

The thread can be unscrewed cleanly. The glasses come from the Japanese house Asahi Glass and appear to have a high-quality finish. I noticed a slight color deviation into reddish. During my tests, however, I found the slightly warmer color temperature appealing. You could easily compensate for this during post-processing. Since my used lens is not susceptible to lensflares, I was happy that there was no deterioration with the filter on. The filter reduces incoming light almost exactly by around 10 stops. The filter only allows approximately 0.01% of the incoming light to pass through. ND1000 means that in order to achieve the same result, we have to expose 1000 times longer than without a filter. This allows you to achieve extremely long exposure times of several seconds to minutes in daylight. I recommend that beginners print out a table to quickly find the right exposure time.

In my attached pictures, you can see the result even with extreme backlight, both with and without filters. I could hardly notice any differences in quality here. With and without filters, there were neither more nor fewer lens flares. These only appeared in other places in the picture. The white balance was set consistently for all shots, manually to daylight, and all other settings were set manually for direct comparison, with the exception of shutter speeds, of course. Here you can see the only slight color shift into something reddish. I was only able to notice a loss of sharpness after 600% magnification, if at all.

So far, I haven't had K&F Concept on my screen in this price range. The price is, of course, an announcement and should scare off amateur photographers for now. However, you don't want to reduce the quality of a lens in the four-digit price segment with an inferior filter, so the investment can also be worthwhile for ambitious amateurs. Because of the impressive optical performance, I give it the full five stars.