The Fotodiox WonderPana 80 Soft-Edge Graduated Neutral Density 0.9 Filter is designed for use with the WonderPana 80 filter holder system. It helps to darken specific areas of an image, such as bright skies, while allowing for a normal, unaffected exposure in the other regions of the image. The filter is densest at the top edge and tapers to clear by the middle, with a softer edged line of transition between the dense and clear areas. Neutral density filters do not affect the coloration of the image and this filter provides up to a 3-stop reduction in light from entering the lens.