The filter is designed with dark area on the top and gradually to clear at the bottom preventing over exposure of skies. Neutral density filters do not affect the coloration of the image and the 0.9 density provides a 3 stop reduction in light from entering the lens. This filter measures 3.9 x 5.9″ / 100 x 150mm and is compatible with the Nisi 100mm filter holder or other 100mm Standard Filter Holder (Lee, Cokin, or Formatt Hitech). The filter can be repositioned in the holder allowing recompose the photo for the best result.
By using neutral density filter the camera is vulnerable to infrared light which will cast the unwanted red color to the photos when shooting at small aperture. Nisi added the infrared protection coating layer to this filter which helps to eliminate the infrared light through the lens to bring back the natural color.