SAXON 1.25" Neutral Density Moon FilterThe saxon 1. 25" Neutral Density Filter is a grey filter. An ideal neutral density filter reduces and or modifies intensity of all wavelengths or colors of light equally, giving no changes in hue of color rendition. The purpose of standard photographic neutral density filters is to allow the photographer greater flexibility to change the aperture, exposure time and or blur of subject in different situations and atmospheric conditions.