The Kenko 72mm NDX filter can be adjusted from ND2.5 to ND1000x. The filter can darken the scene by anywhere from 1.3 to 10 EV and allows the use of wide apertures while keeping the correct exposure within the shutter speed range of your camera. Its variable nature allows the amount of filtration to be reduced for focusing, then increased to the desired amount, without having to remove the filter.Please note that the filters can vignette when used with lenses wider than 28mm equivalent.