The Nano-X Magnetic Filter Set from K&F Concept - an in-depth review

[@joakimengel1767]

Honestly had not expected this …its one of the best and most thorough reviews I have come across (and I have seen quite a few on camera gear!) attention to detail and giving it the time needed to explain is just very enjoyable and informative! Thanks :-)

[@michaelmckeag960]

I just purchased a set of Kase filters (CPL, ND8, ND64, ND1000) plus adapter rings. Your studio test for color cast is ingenious. I will apply your method to these filters using a Macbeth chart as the target. I was also about to test a cooled CMOS Bayer array astronomical camera paired with a 220-deg circular fisheye lens for similar effect. You have just provided me with a promising method. This camera and lens are intended ultimately for acquiring data from which quantitative night sky brightness maps can be produced.

[@rickymcc9072]

A pretty fair review IMO and shows the merit of testing. K&F do seem to offer decent quality at a very accessible price. I have lost count on the number of filters (and diff systems) I have bought and used over the years for photography and video, some complete rubbish and some uber expensive. I learnt a lot, not least that you don't always get quality by paying a high cost. I wasted lots of ££$$ making mistakes, so if any of my learning(s) can help others then my notes aren't a complete waste of time. These K&F are OK, but a weakness apart from stopping you using a hood is falling off whenever knocked. Given that magnets weaken over time I'd suggest photographers thinking twice about whether these are the best magnetic filters (unless you are budget limited and determined to have magnetic utility - advantage is principally speed of switching). My approach here (magnetic filters) was eventually to spend a lot more and buy Maven magnetic filters. I had previously bought K&F in screw thread too (good, but risk of binding, slower in field to use but does permit use of OEM hoods, unless also using step-up rings). Maven filters cost a lot and I avoided paying that much for some time, but eventually realised they weren't as expensive as my many lenses. Also, as long as one can afford it, then worth considering IMO. My trouble is I end up buying lots of stuff, often after biased reviews, only to realise later I should have saved up, carefully done my own research, then bought smart rather than buying twice or thrice. Often, but not always, it's better quality kit in the upper quartile of cost or, more typically, near the boundary between second and upper quartile in cost range that offers the best overall value IMO. NB this principle applies to lots of stuff not just filters - tripods, lenses, shoes, clothing, cars, computers etc etc. I also learnt it's a good idea to pre-test everything, prior to serious use, so you understand the strengths, limitations and can then operate confidently, within known parameters. I now do test shots for both lenses and filters. Related to this, there is merit in doing a custom white balance in the field (more important for video where shooting in RAW is almost impossible). RAW for stills shooting is easy and advisable for maximum flexibility and control in post. Video use: VNDs (typically used in video for speed and convenience to achieve the 180 degree shutter rule) can be a particular problem (weird colours) so again an in-field custom white balance is good idea. Even the most expensive VNDs (eg Polar Pro) have limitations. With wide lenses there can be differential colour tones across the panoramic field of view. Budget VNDs can be very problematic. That said I can use my Polar Pro VNDs successfully, within narrow, known, operating parameters for speed and convenience (typically not uber w/a). Best solution I found is to use a range of high quality fixed NDs. Eventually, after much trial and error, I ended up buying a range of NDs in 4x5.65 inch size (AKA cinema style filters) for use in a matte box. This approach is both expensive and cumbersome, but works when you have time and demand the best in quality. It can also help with wide angles too, where typically no filter can usually be fitted - as with my Sony 14mm f1.8 (stunning optical performance but suffers from a convex front element, fixed hood, no filter thread). I can use this extreme 14mm lens, with a rail mounted matte box, cinema size NDs and zero vignetting. It's cumbersome, slow and won't suit most, so not recommended. It requires the lens/camera to be rail mounted and protruding into the rear of the matte box. Black velvet of black cine foil could be used, optionally, to block any stray light entering from behind too (but I haven't yet found the need for that). OK I admit to being both a nerd and obsessive. I'm also fortunate in being able to afford pretty much any kit I want. But I now understand that a good pre-assessment of your real needs, clear review of available market options and getting a second or third opinion is a good idea before spending. Also being wary of sales (Black Friday etc) unless also fully meets your real needs etc. Good maxims one might consider .... "buy in haste repent at leisure" or perhaps "buy cheap, buy twice" - could have saved me a lot of money over the years. I used to also buy stuff (kit etc) on whim, which lead me to make many mistakes. Now I try to add things to my "maybe list". If after a few weeks it's still wanted then I might buy - this 'personal rule' now saves me wasting lots of money and I'm reminded that things are usually 'cheap' for a good reason. Finally, in quest of a better, simpler life, a belated realisation that there is only so much stuff (kit etc) that one can ever use, appreciate, carry, store, eat, live with etc so it beholds one to make good choices and consider simplifying, streamlining and divesting oneself of unused, now unloved, surplus stuff that really isn't 'part of the solution'. But I digress.

[@Mike-VR]

Sir Allan! That was very well explained. Many thanks for your efforts.

[@johngabris9690]

superb review guy knows his stuff brought back so many memories from my learning days

[@peterkumble4093]

Excellent Allan, many thanks! I have been leaning toward the K and N system. I will agree that the limitations with a lens shade mounting with the magnetic filters is an issue. Again, thanks for a very informative vid.

[@mongoose9594]

Very informative and impressive effort with the diagrammed etc (and love your dry sense of humour too 😂). Liked and subscribed.

[@maxheadrom3088]

Thanks for the explanation about the CPL filter! So the autofocus would have problems if polarized light hit the sensor so they add a second layer that creates circular polarization. Thanks!!! 13:00 CPL filters work because the sunlight when it enters the atmosphere it polarizes the light (like any reflection or change of medium do for any non perpendicular incidence). This polarized light then scatters on the suspended particles in the atmosphere and that scattered light is not polarized so if we align the polarization of the CPL with that of the sunlight then we'll increase the non scattered light relative to the scattered one. 17:20 The coatings are impedance matching coatings that avoid reflections. Light can be understood as an electromagnetic wave and just like in RF cables, if the impedance is not matched it generates reflection. The impedance matching works on the interface so they'll work in both ways (outside in and inside out). A good example of impedance matching are the three little bones in our ears that match the impedance of sound in air to that of found in the liquid that fills the cochlea. In that case it's a lever with a moving fulcrum with the longer arm connected to the timpani and the shorter arm to the cochlea. Small muscles shift the position of the lever relative to the fulcrum. Now, if we go into a swimming pool and dive we won't hear the music because the sound will reflect off of the water surface. Another example is cars on a highway that near a bifurcation will slow down and that creates a reflection - a wave of cars breaking before we can even see the bifurcation. The impedance in this case is the relationship between how many cars can flow in the highway each given time period (cars/minute). When cars are faster or slower, the same number of cars might flow given when we're slower we can drive closer to other cars but the problem is how to make cars slow down in such a way that no car will have to do it to quickly (that would cause the impedance mismatch). The solution in highways is to make put lots of signs, numbers on the lanes and on the signs showing ahead of time which lane one should choose for their destination and also making the bifurcation as long as possible. In lenses, the impedance matching is done by adding a series of coatings with impedance nearing, on the outermost coating the air and on the innermost coating the glass - a solution similar to the one used in highways - so the most coatings the filter or lens have, the better. Oh ... btw, next time you get sun glasses look for one with anti-reflective treatment on the surface that faces your eyes - you'll like the result!

[@xmgarcia]

Thanks Alan! Really enjoyed your review! 👏

[@josecarrillocabrera2508]

Amazing explanation. Thanks for taking the time!

[@edgarthart]

Thanks. I did need to speed up the player by 25% of even 50% speedup makes it bette to follow. So articulate very well, but it can't keep my eyes open at the default pace. 😀

[@huaxingwang9163]

Hi Allan, I still enjoy this video after 3 years. I wonder what kind of ND or VND filter did you use for this video? Thanks.

[@michaelmckeag960]

I applied your method to my new set of Kase filters using an X-Rite Color Checker as the target and a pair of 5500K floods (~5700K CCT measured with UPRtek MK350N spectrometer because I happened to have one available). Set in-camera WB to 5700K. Test shots with Nikon 105mm f/2.8 on D850 @ f/4 ISO 64 aperture priority. No filter: 5800 +15, ND8: 5850 +6, ND64: 6000 +21, ND1000: 5800 +33, CPL 5500 +22. The color shifts relative to no filter were ND8 +50 -9, ND64 +200 +6, ND1000 0 +18, CPL -300 +7. Now I will have to try this with my old Lee filters.

[@SteveKershaw]

Great review, I got the same set, I also added a 6 stop, this came with a magnetic filter cap, this cap is amazing, I ordered 3 more so I have my main walk around lenses set up this way,

[@alasfour2000]

Thanks Allan.Really enjoy watching your videos.

[@NJM1948]

What an excellent video - very well articulated and informative. I have been looking at a filter system as I am now more into landscape photography and longer exposures. What I didn't pick up from your talk was the availability of step rings. I have lenses with 3 different filter sizes 62, 67 and 72 so would need step rings to use on different lenses.

[@AllanWallsPhotography]

Hi Nigel, Thanks and you are right - I didn't;t cover the sizing well. The kits come in all the usual sizes (82mm being the largest). What I would suggest, as you really can't use a lens hood, get the largest size you need and a set of standard step up and step down rings. They come in so handy and the cost of a set ($20) is not much more than buying the two you would need. In your case, get the 72 filters and then use the 62-67 and 67-72 step up rings or the 67-72 step up ring alone for the smaller lenses. I shoot with 77mm lenses but I got the 82mm filters to reduce the risk of vignetting , so you could go to the 77 and still be able to use the 62mm lens. By the way, I am reviewing two new ND filters (ND4 and ND6) that just came out for this magnetic system. Very useful added range. Hope that helps!

[@Zizos]

Is there some color cast with the 3 and 6 stop too? I wonder if it's consistent or if the 3 has less cast than the 6.

[@iainguitar]

Excellent review Allan. Thanks. Knowing the exact colour cast of the ND is really useful. I've just ordered a set. I've no intention of using the UV and I won't be shooting wider than 24mm so I should hopefully be free from vignetting.

[@ken.gibson.photography]

Thank you - This is really helpful. I'm looking at Kase Wolverine and Urth filters - this has me giving K&F a second look. I have the K&F Nano X MRC CPL, which seems to work fine for my needs, so these may be worth looking at.

[@alanrecktenwald4239]

I've been using the Kase Wolverine Magnetic filters. I have same issue with lens hood. Sad it is as such considering how easy it would be to offer a magnetic hood. I chose filters to fit my largest filter size and rings to adapt. You would only need one size hood in two configurations, tele and wide. Thumbs up Allan

[@braddahjerry]

I was trying to find a comparison video between Kase, Freewell and K&F when this video popped up. I was leaning heavily on the K&F for the price and the compact/waterproof case. Your video helped me confirm my decision in buying K&F. Thank you!

[@AllanWallsPhotography]

After a couple of months I am still using these regularly - I think you will like them!

[@philipedwardcaddick4294]

I have just bought this set and my camera is a Sony a77 and I have a sigma 10-20mm wide angle lens and I have not seen any vignetting even at 10mm . The only thing that I can think that may have prevented vignetting is my camera is a cropped sensor

[@michaelmckeag960]

It belatedly dawned on me since I have a spectrometer (for conducing outdoor lighting inventories for International Dark-Sky Association dark sky place certifications) it provides the most direct and comprehensive means for measuring filter color shifts. I used a Porta-Trace light panel as the light source, and held each filter in front of the spectrometer lens during each measurement. The spectrometer outputs are extensive, but correlated color temperature (CCT) provides a useful summary for this task. Light panel CCT: 5900K. CPL CCT: 5550K (slightly warm shift). ND8 CCT: 5740 (smaller warm shift). ND64 CCT: 6135K (slightly cool shift). ND1000 CCT: 5965K (very slight cool shift).

[@gettons1980]

Really informative Allan!!!

[@Reddo136]

I have a simple question. I suppose you are speaking as for full frame lanses when talking to vignetting. Is that right? I'll then be fine to 16mm with APSC lenses? Thank you very much for your work!

[@moshebrener5515]

hi, great video, thank you. why not solving the vignetting issue with a larger filters? like 82mm or even 95mm. the only downside i can think of is the hood. what do you think? any other downsides?

[@parranoic]

Your sensor IS sensible to UV and IR but you already have a filter in front of it, the part that people usually clean or scratch is not the sensor but the UV/IR cut filter

[@GlennMartinez]

Well done! I try to buy the largest mm set and use step Up/down filter adapter rings . Thus the one set fits 90% of my lenses . Great review!

[@SmallSpoonBrigade]

Those are probably fine as long as you're not stepping down too far and don't mind them blocking your lenshood.

[@Glasairman]

Do you have an opinion on buying the K&F 82mm set and adapting down to 2@77/62/49 or rather buy the 77mm set and for the (rarely used 82mm big Tamron 150-500mm) adapting up. Any downsides optically?

[@gorannilsson4721]

very very VERY excellent video.

[@wrecktech]

I've been using Manfrotto Xume magnetic filter adapters and rings for several years. All you have to do is put the ring on your currently owned filter of choice and put the adapter on your lens. No limitations on filters you can use.

[@jetfightercn]

Excellent explanation! thank you.

[@brice3513]

I wish you would've explained how to attach the polarizer. Very confusing. 😛

[@acekat7009]

2nd part of my question:can i fire the flash on camera with jjc hit shoe and cold shoe adapter?without buying the pc synch chord? Thank you

[@ColdCoffeePhotography]

Amazon code doesn't work for us in the UK, also wished it included a 6 stop ND rather than the UV filter

[@AllanWallsPhotography]

I will let them know - I'm sorry about that. I never go anywhere with out a Haida 6-stop.

[@Those_Weirdos]

The UV filter, for me, is just a sacrificial surface to worry less about than my expensive lenses. And if you absolutely positively need every last nanogram of sharpness, you can always remove it. The magnetic system makes that especially easy.

[@berthaduniverse]

Been looking at these. I even tried to get them on Amazon, but it's not very well marketed, and the last thing I want is another UV filter... Thanks again Alan...

[@AllanWallsPhotography]

Thanks Paul, The ND is really quite impressive and I love the low profile. Big step up for K&F, I think.

[@berthaduniverse]

@@AllanWallsPhotography I'm glad you talked about color shifts in ND filters. I do time lapsing, and I used to try ND filters for the holygrail shots, and I found some ND filters actually effect ranges of color differently. I'd like to see you trying a color card too. Luv you channel Alan, great job.

[@michaelmckeag960]

Your mention of aluminum filter rings being more prone to getting locked than brass was a “duh moment.” The obvious difference is the linear coefficient of thermal expansion (21-24 vs 18-19 E-6 m/(m C)). If that is the case then you can turn the larger coefficient of aluminum from your enemy into your friend by cooling the lens (and the jammed ring).

[@AllanWallsPhotography]

That's what I do when I'm at home. But they only get stuck out in the field - where everything is hot! And thanks for the excellent work on the color casts - I'll be getting back to you on that.

[@acekat7009]

Hi Allan,hope you are doing very well and you and your family are safe. This is a great video,i never heard of this magnetic filter.It just sounds great. Allan,i just read one of your blog/article regarding a macro set up where you talked about a Jjc hot shoe and cold shoe on a flash for macro flash photography.I really liked it,i think it will definitely help the flash to come forward in an angle on top of the lens. I have one question regarding that,the sync chord that you mentioned in that article in the end,what is it for?sorry i didn't understand that part in the article,i am a beginner.Is it really necessary to buy along with the jjc hot shoe and cold shoe adapter? Thank you very much,i love your vids and really enjoy learning from it.

[@AllanWallsPhotography]

The adapter that I described has no electrical connection to the hot shoe. The articulating part is all plastic. So by connecting the hot shoe to the camera with a PC sync cord, you maintain control of the flash. You can also do this wirelessly, but there is a close-limit, at which point wireless flash behaves erratically. This avoids that problem.

[@acekat7009]

@@AllanWallsPhotography Thanks you so much Sir,i have ordered the male and the female adapter and sync chord to connect my Nikon d300 and yongnuo 560 ii manual flash.Can't wait to try it!🙏

[@marcgravel2331]

Do you still stand behind these filters today?

[@stubrides8766]

This kit would certainly benefit from losing the UV filter and adding a 6 stop ND. In my humble opinion. Or even keeping the UV as there is no magnetic cap..

[@AllanWallsPhotography]

Hi Stu, I didn't think about that when reviewing them but that is exactly what I did with mine - added a 6. But since getting the 100mm square set I haven't had them on the camera. I do like them though, perfect for travel.

[@Jabber-ig3iw]

The UV filter goes straight in the bin🤷‍♂️ completely pointless things.