K&F Concept67mm ND2-400 Slim Variable ND Neutral Density Filter Adjustable Fader ND2 ND4 ND8 ND16 to ND400 Lens Filter + Microfiber Cleaning Cloth for DSLR Cameras (Nano-B Series)

Update: Customer service team reached out to me and explained me how this work. It drastically made difference and enhanced my understanding about the product. I am upgrading my feedback and a big thanks to the customer service team. Definitely would recommend them and their products in future.

I have been taking photographs since the mid 1970s and over the years have gone through my fair share of filters, square, round and even homemade.This K&F filter comes well packaged in a sturdy plastic box which a foam insert designed to securely hold the filter whilst being transported. The insert has recessed finger holes for very easy removal of the filter even with cold fingers. On picking up the filter the first thing you notice is how sturdy it is and how velvety smooth the movement when you twist the outer ring. I have purchased lower-priced filters before and sometimes been very disappointed in the mechanical construction but not this time as it is on a par with many more expensive filters in my collection.I purchased this to use on my Nikon lenses when shooting video. My normal choice of filter is the square system but at present for video use these screw-in ND faders are by far the best option for my money. One of the first acid tests for any filter is how well it attaches to the front of the lens and this one did not disappoint. Straight on, first time with no fuss or fumble.The filter rim sits proud on a Nikkor 24-70 f2.8 making the outer ring very easy to grip when adjusting the strength of the ND filter. This is a relatively slimline filter and as with other slimline filters I have used the lens cap does not feel very secure attached to the front but this is not an issue with this type of lens as I only have it attached whilst I’m actually using the camera.Whilst I have not had the chance yet to try the filter in all conditions my early conclusions are very positive. Physically using the filter is very pleasant because of the smoothness of operation and there are handy markings around the rim of the filter showing maximum and minimum positions.On a dull day like today, shooting with a Neutral picture style I found the images taken with the filter lacked just a little contrast compared to those with no filter. I doubt that it would be as noticeable on a bright, sunny day (when to be fair an ND fader is more likely to be needed) but in the event it was not a major issue as I simply tweaked the contrast up a notch or two and created a custom picture style which worked a treat. As soon as we do get a bright, sunny day I will test the filters again and if my assumption regarding contrast proves wrong I will post an update below. However, with a 1,500 mile wide storm due to batter the Uk over the weekend don’t hold your breath!I have other K&F products in my kit bag, including lens adapters, and would not hesitate to purchase this brand in the future. On my personal experience to date they are well constructed and represent very good value for money.This filter represents incredible value for money and the small niggle with reduced contrast in dull conditions does not give me a reason to reduce the star rating. Had I paid around the £100 mark for the filter then all other things being equal I would certainly be dropping one star but at this price point that is just being curmudgeonly.Please note that whilst I have reviewed the 77mm version here I have also purchased a 67mm version too for use with a Samyang 12mm lens on a Fuji X-T10.

Bought this with a uv filter as it luckily fit 2/4 of my lenses. The micro fiber clothes are nice and the storage box it good but i prefer the round one(my 49mm Variable nd filter has a round tub). It screws on and off very easy maybe a little too easy as if its not on tight enough you can unscrew it from adjusting the nd. Speaking of, the adjusting is smooth but it can spin a full 360 degree which is a bit annoying considering my other 49mm K&F Variable nd stops at max and min points. Im hoping this is how its supposed to be and its not broken.

Great product and an even better price. Produced Great clear pictures

Filter is of great quality and build as of most K&F products. Unfortunately, It has a slightly larger diameter of outer thread than inner so it doesn't work with a lens hood on Lumix S series lenses. Not an issue but just something to be aware of.

As an inexpensive way to delve into long exposure photography, this is perfect. It does have some drawbacks. One is the stepless/stopless rotation: you rotate the filter until you get the desired level of darkness, but if you keep turning too much you go all the way back to the "bright" end. Plus it doesn't lock in place, so you have to be careful not to touch it.It gives an adequate variety of darkness, allowing >20 second exposures.Very occasionally I get the X/banding but very rarely.

Have been using this ND filter for a few year and it's fantastic for the value, however my Sony lens cap falls off so easily from it, and numerous times I've noticed it had fallen on the floor a few steps back. At extremes of the filter are also visible overlap but my main gripe is the concern over losing my Sony lens cap. If this thread was tightened it would receive one more star.

Very high quality product, and the resulting images are gorgeous, but I do have a slight issue in fitting it on the lens - I've got a nifty fifty with a 49mm filter thread. It does work brilliantly once fitted, but it takes a bit of nudging about to get it fitted.