The Formatt 5.65 x 5.65" 81EF Hard Edge Graduated 0.9 ND Combination Filter combines both a warming 81 EF and a graduated neutral density filter. There is a hard-edged 0.9 density for darkening skies and other bright areas of the image. The 81EF filtration covers the entire filter plane and adds more warmth to your images in order to reduce blue shadows and haze when photographing outdoors and with an electronic flash.
The 0.9 density provides a 3 stop reduction in light from entering the lens. This filter measures 5.65 x 5.65" / 143.5 x 143.5mm and is constructed from specially formulated CR-39 resin sandwiched between two layers of high-quality Schott glass.