I have been learning more about photography and as time has permitted I have been improving my skill as an amateur photographer. I have worked with other types of filters, in particular CPL and FL-D filters, but before now I have never worked with ND filters. I have been able to achieve good results with it and so far I am pleased with this filter though I know I have more to learn about it.A neutral-density filter is used to reduce light reaching the aperture without fiddling too much with the colors. This allows one to get creative with shutter speeds. This particular filter is adjustable and turns on the lens body face, allowing the photographer to increase or decrease the amount of filtering done. At the lowest setting the filter does very little filtering; when turned up to the maximum filtering level very little light gets through and a moire pattern appears so I do not recommend turning up the filter to this level.To get a feel for how well this filter works I took my camera outside as a big thunderstorm approached and took some pictures of one of the cloud formations. I selected two pictures from that set, one where I did not use the filter and one where I did use it on about 1/4 strength. Although the filter evenly reduced light levels, the color contrast in the filtered image is much more pronounced and obvious.The most common use for this kind of filter is to reduce the light levels, then take an extended exposure for a scene with motion, such as a waterfall.This is a very nice filter and I could not be happier with it. It is very easy to use and it really works well.Disclaimer: I was provided a sample of this product in exchange for a fair, honest and thorough review. Even though I received this product at no cost I have rated and reviewed this product without bias, based solely on my experience with it.