took the opportunity to test an ND filter from K&F, as I've been very satisfied with most of their products so far. ND filters are particularly useful for darkening fast lenses in strong sunlight without drastically reducing the shutter speed or closing the aperture—and thus losing the desired bokeh. I was pleasantly surprised by the filter. The brightness can be continuously adjusted by simply turning it—a huge advantage. Since this is a cheaper option, there's no magnetic function, for example, where the filter can be easily removed if it's not needed for a short time. Only the screw-on ring remains on the lens. I missed that in this version. K&F's high-quality workmanship and well-thought-out packaging convinced me. However, I would personally opt for a cheaper alternative, as I rarely need the filter for my video recordings. However, it's a great option for occasional use. Note on the Vine program: I received this product for free as part of the Vine program. I only test products I actually need and rate them honestly based on my own experience. Neither Amazon nor the seller influences my reviews.