so let me start off with this, i dont usually write review about lens filter because most of them are just good and ive never had problem with any of them since my canon 60D era.lol but recently ive got a little issue with one of my main filters that i only used a few times so far since its only being used on one of my main lenses to shoot weddings and enggagements only. one morning when i took it out of my camera case then attached it to my A7siii to get them ready for a shoot, after some inspection, i found micro scratches right in the middle of the filter! i was shocked and little bit annoyed, because it never been dropped, rubbed against anything! so i emailed the company an hour later and got a response later on that day. after emailing back and forth including sending them pictures, the very next day they said they will send me a replacement and would be here on monday! it was so easy to work with them although im glad i had spare filters incase of emergency situation like this happens. it might have been one in a million deffect from their factory but it surely didnt scare me enough to stop buying their products in general!

ps: the scratches seemed doesnt affect or degraded the picture quality at all, but i wouldnt use it for professional shoots anymore.

One of my greatest concerns when purchasing this filter was its wide focal lens performance, which I can understand is challenging due to light physics.

After testing on my Sony PZ16-35 lens:
- At 16mm focal length vignetting is not usable and needs to be cropped.
- At 17mm it is very light and hard to notice, very usable to me.
- At 18mm I can't see it at all and looks great.

I uploaded 5 images to this review (pardon the high ISO, as I tested the filter at ND32). Focal lens of each pic: 16mm, 17mm, 18mm, 19mm, 20mm.

I am keeping this filter because I don't think I'll be able to find a filter that accomplishes no vignetting at 16, but I wish companies were more upfront about which exact focal lens their filters support well.

I come with a long history of taking photographs with filters for special effects. I have used Cokin systems where you can share one filter with various lenses with adapters. I own over 50 such filters and lately, I am simplifying my camera bag and traveling with only a few filters. My most popular filters are the graduated neutral density (ND) filters. With these, I can rotate the filter to my preference on each shot. BUT that means I have to carry more than a few of the same ND filter but at different stops.

Solution: The K&F Concept Magnetic Variable ND Filter offers me an option to use one filter covering 5 stops within seconds. That is great timesaver as my shots of landscapes or sunsets sometimes requires swift framing and adjusting to rapid light changes.

ND filters are an investment to your camera gear. These will filter out very bright light and allows the photographer longer exposures during daylight. My favorite use of ND filters is to have water movements look silky while capturing the surrounding in detail. This K&F Concept filter is built amazingly well. The glass is better than my Cokins. Since it is built to specific lens size diameters, I had to rationalize which lens I used the most and ordered that size. 58mm in this case.

The case is a worthy vault for this filter. Kudos to the team that designed that feature. The magnetic ring screwed nicely into my existing lens. In fact, it screwed in too tightly, it took me 10 long minutes trying to unscrew it later on.

The magic is with the magnetic technology. Wow! It was instant on and instant off for the actual ND filter. Amazing. With that also comes the fear of dropping the filter. I fear that a bump will dislodge it so I kept my hand on the lens at all time. If you are in stationary setting, you should be fine.

This lens filter is a great tool for many future vacation shoots. Simple to carry and use.

Do note you cannot place a regular lens cap over the ND filter. Bummer.

Overall, I love the new direction that these ND Filters are headed. It is less fuss and more time spent on the actual shooting pictures. Give this a try. I do recommend this variable ND filter.

This is one of the best additions to our camera since we got it. It is very easy to install and once in it stays put due to the alignment slots on the back side.
Adjusting it is very easy once it snaps in. We like the infinite variability, it allows you to perfectly tweak your settings for each scene.

These are cool for the price awesome.

I’ve had this filter for 9 months and love how easy it is to use. The only drawback is the magnetic grab isn’t the strongest. I was at a tower and accidentally knocked it off and watched it fall at least 75 feet and bounce on a platform. Thankfully it wasn’t too busy and I found it and it still works! It doesn’t adjust quite as smoothly after the fall but I was happy to not have to buy another.

I’m more pleased with this than I even expected. The magnets are PLENTY strong enough. As a matter of fact, the magnetic lens cap is so much nicer and grips better than my original pinch plastic caps. The ND filters do what they should and the image quality doesn’t suffer. They don’t seem to add any color cast. Very happy with this brand, so much so that I have them on all of my lenses. Pricing is less than several
Much higher priced brands and quality is on par with them.

This is so helpful, I don’t have to worry about unscrewing my ND filter and it saves me time in between shoots. Every second counts for videos.

Over all build quality and design is very good but Having vignetting with 24mm lens, Best to use with higher focal length than 24mm

This is a good adjustable neutral density filter with no problems I can see. It uses K&F's special coatings to help repel dust, water and fingerprints. This filter has a magnetic attachment system, there is a magnetic ring (with no glass in it) you screw onto your lens. Then whenever you want to use the ND filter you just pop it on and pull it off magnetically, making it easy to change. The system seems to work well, but it's the only one of their filters I have which features it. By rotating the filter you can go from ND2 to ND32, or 1-5 stops.

A lot of people wonder what this kind of filter is for, basically it lets you get some different effects when you are shooting in direct sunlight. For example, you can open the F-Stop of your lens all the way to get a shallow depth of field effect, then use the ND filter to darken the image back down so it is exposed right. Another common use is so you can shoot with longer shutter speeds in bright light. This will allow you to get that effect where moving water has a soft motion blur on it by setting a longer shutter speed and adjusting the exposure with the filter. It's also very handy for shooting video in bright light. Using a high F-stop and shutter speed for this can give you a video that has no motion blur and appears to stutter when the camera pans. The ND filter can allow you to shoot with longer exposures which will give motion blur and a smoother more cinematic look when panning.

So overall a very useful filter to have if you do videos or photos outdoors in bright sunlight.