K&F Concept ND8-ND2000 Nano-D Variable ND Filter with Multi-Resistant Coating (49mm)

In my case, I tried a 77mm. The guide marks did not correspond to the reduction steps. The reduction only occurred almost at the end of the brands. The reduction factor does not apply either. The test I did, goes slightly under 3 to 8 steps (actually 2.5 to 7.5 steps)

Hey guys, all vari ND filters work by combining two circular polarizers together. So, unless they employ hard stops on the rotation, you'll get the big ugly black cross effect with any of them. This one is no different, so you just have to realize how they work, and plan your exposure accordingly. I'd say they're probably 3-9 stops of usable range, beyond which things get dicey. They render a fine image, and so optically, I'm pleased with them. The price is right, and when you're in the heat of a shoot using a bunch of primes, it's nice to have them already attached on every lens in the kit, so I bought three, and I'm totally satisfied with them. Using them on the Samyang V-AF series lenses, and there's no vignetting on even the 24mm. I don't have the 20mm to test, but I'd be willing to bet they're OK there, too.

I bought this filter to use with a 24-105 lens. At the wider focal length you can't use the higher density of this filter. For example, at 24-50 you can't use the 3 darkest settings. Once you get over 75mm to 105mm then you can use the darker/darkest settings. Don't expect 11 stops of dark at 24mm. I'm not sure if I'm using it wrong or what but I've never seen this before.

I just bought this filter because it is 82mm and promises to go darker than my Tiffen and Singh-Ray variable NDs. First use of the KF today, and I am very disappointed. Of the 3 brands, Singh-Ray is by far the best, but most expensive. With Tiffen, sometimes I get dark edges at wide angle. The KF delivers poor results compared to the American filters. Clear, huge black X across the photo at high setting, esp wide angle. I've never seen that with other brands. Yet their marketing says the opposite. Adjusting the filter one stop at a time (ie 1 dot at a time) does not equate to one stop. Instead it is totally unpredictable. You could be totally underexposed at one dot, turn the filter by one dot, and be totally overexposed at the next dot. Also there is a distinct colour difference. Not happy. The lesson is this: stick with proven brands, not wannabes with big marketing budgets .

It works and for the most part, it is just as good as the expensive filters of its kind. The only issue is the last set or two on the darkest settings that there is an issue. So I never really use the last two max settings. Other than that it has been great. I don't see the point in paying for something more expensive, so it is great for budget photographers without going cheap and getting disappointed.