I tried the 46mm diameter filter on a Nikon Z30 with a Nikkor 16-50mm lens. The filter fits perfectly into the filter thread of the lens.
When held against the light, the coating of the filter glass becomes visible. A green shimmer can be seen, which indicates an anti-reflective coating. The glass itself was delivered in perfect condition.
I did not notice a reduction in light intensity through the filter. With the same exposure time, aperture and light amplification, I could not see any difference in the brightness of the image.
Well, how does the filter work, or rather, where is the best place to use it?
When photographing or filming direct light, such as light tubes or LED bars, the light is scattered by the filter in such a way that it looks like fog around the light source. The areas around the light source become more diffuse and the light source itself becomes very blurry. For the best effect, as much light source as possible should be visible in the picture. Objects in front of the light source are only slightly distorted by the filter.
The first test shots convinced me of this filter and I am totally enthusiastic. It's definitely an asset to my recordings.