37mm Variable ND3-ND1000 ND Filter (1.5-10 Stops) Neutral Density Lens Filter with 24 Multi-Layer Coatings for Camera Lens

My wife and I are picked up a couple electric scooters and I thought it would be good to mount our GoPro and get some video, so filters are very nice accessory that can make a big difference. This filter is just amazing well made, such high quality and beyond. Perfect all the way around. Screws on to my camera enclosure perfectly. Filter adjusts very smoothly and it's surprising how wide a range it has. i am no photography expert, so sure it will take me some practice to get it down.

Filter comes in a nice plastic case to protect it. I only wish it came with some kind of lens cover to protect the lens when it's out of the case. I can just take it off each time, but would be nice to leave it on.

Very nice filter, price is good, gladly recommend.

Out of the box this filter is well made, threads on and adjusts smoothly. The optics are quality and I was pleased with the photos. I did experience some vignetting when pushed to the limits, but that might have been caused with me having the UV filter still attached and like I said that was at the very extreme end of the filter position. Very impressed with the filter and it's quality. The photos were F8, ISO 100 and 1/160,1/25 and 1.6 sec. Would buy again.

This is a filter feature I have wanted for a long time but always considered a multiple filter set, not a single variable filter. To my satisfaction I found this single variable filter works very well and takes up minimum space in my camera bag. The effect given by this filter is also such that I don't have to worry about losing sharpness due to an inferior piece of glass. I use it primarily on my Canon EOS M50.

I have come to rely on K&F for a number of filter types for my many lenses. They are well made with quality glass and I have yet to find any real faults or negatives in these great value filters. You would have to pay a TON more for filters that are only slightly better than these!

This variable ND3 to ND1000 filter provides highly capable ND correction from 1.5 to 10 f/stops. It is a 67 mm filter that is widely used...especially for the majority of Tamron lenses as well as a plethora of Sigma, Sony and Canons as well, which makes this filter an even better bargain.

The variable range is done simply by rotating the front dial of the filter until just the right ND level is found in the viewfinder. The filter features 24 multi-layer coatings to provide the clearest and distortion-free optics, using Japanese glass (Excellent) and precise CNC machining.

I can honestly say that this variable ND filter is almost as good as filters that cost as much as five times more. Construction is very good and the filters mount to appropriate lenses without drag, rubbing or other issues. Simple operation and fantastic results!

All in all, and especially at the value price, this set earns an easy FIVE STARS with me, and I can honestly and heartily recommend the set for your appropriate lenses.

Very good image

If you are new to photography this is a good filter to start with

I'm becoming a fan of K&F Concept filters. This is my third filter from them and so far I've been extremely impressed with the glass.

CONSTRUCTION
The filter attaches to my lens smoothly and comes off without binding. The frame is machined very well with a semi-rough coating that makes for a secure and confident grip on the filter while adjusting it. Adjustment is very smooth with quite a bit of resistance and won't change if you happen to brush up against it. You can gauge the VND effect with markings on the edge that range from "MIN" to "MAX" with a series of square dots that gradually increase in height.

VND filters tend to be thicker and can cause vignetting with shorter focal lengths. K&F's solution to this is to make the filter slightly larger than the lens diameter (about 71mm on the 67mm filter I'm reviewing). This works great to prevent vignetting but it means that you can't use your existing lens cap. Using a lens hood is theoretically possible but the larger size means it'll be very difficult to set up even if it fits.

I have another K&F filter set that came with really nice machined caps. With the larger front ring diameter that doesn't fit your lens cap that would have been a great add.

TESTING

This filter is specified to produce 1.5 to 10 stops of light reduction. I measured approximately 1 1/3 to 12 stops of light reduction with no visual artifacts such as the dreaded "X" effect you get with some VND filters. The filter imparted a slight warm cast (~300K) that remained consistent throughout the range getting slightly warmer only at maximum.

K&F state that the filter markings are not calibrated. I measured the effect under relatively controlled conditions and found that the VND effect isn't linear but instead starts off slowly but increases much faster as you approach max. Because of this adjustments at higher strengths can be quite tricky.

I would have really appreciated calibrated markings to make adjustment easier, but since it doesn't have this feature I measured the approximate strength and made a chart.

MIN
Solid 1-4 = 1 1/3, 5-6 = 1 2/3, 7-8 = 2, 9-10 = 3, 11 = 4
Hollow 1 = 5, 2 = 7, 3 = 12
MAX

You can ignore the Min and Max markings since they don't produce any meaningful changes.

SUMMARY

With this filter you're getting great neutral glass that's comparable to much higher-end products at a much lower price point. Even with minor negatives it's a fantastic all around value. Highly recommended.

PROS
Minimal color cast (+300K)
Adjustable from ND3 to ND1000 (1.5 to 10 stops)
Multilayer coatings for glare reduction, resistance to skin oils and easy cleaning
Does not vignette
Graduated markings from 'min to max'
Threaded front ring

CONS
Filter is larger than the lens diameter
You can't use your lens cap or lens hood
Markings are not calibrated
VND effect is decidedly non-linear and tricky to adjust at higher strengths

With this filter you're getting great neutral glass that's comparable to much higher-end products at a much lower price point. Even with minor negatives it's a fantastic all around value. Highly recommended.

Good quality of the filter. Use this filter for landscape photography is very happy.

I have wanted a ND filter for some time, and a variable ND is just the right thing! Using a ND filter allows you to take much longer exposures while keeping the aperture wider open particularly during daylight hours, all while maintaining a NEUTRAL color effect on the picture. I got the 77mm as that fits both my 24-70 and 70-200 lenses, and I can adapt it down to fit a couple other medium range zooms I have.

I really like that the inner ring has textured grooves which greatly simplifies tightening and removing the filter from your lens. Turning the outer ring is firm, but not overly stiff, yet tight enough to stay where you put it without easily turning.

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