The Formatt 6.6 x 6.6" Graduated Reverse Neutral Density (ND) 0.9 filter is a unique filter that enables you to photograph sunrises and sunsets whilst retaining foreground detail. Traditional graduated neutral density filters filter from the top to the bottom of the filter and allow you to balance a bright, contrasty sky with a dark foreground. However, this innovative filter works completely opposite. The transition begins in the middle and moves upwards, allowing you to control the light where it is most intense (at the horizon) whilst preserving foreground detail.nnFormatt, a company with three generations of experience in manufacturing professional filters, produces each filter to the highest technical standards. The finest materials, combined with cutting-edge production technology, have resulted in a level of optical excellence unmatched elsewhere.nnnNeutral density filters have four main usesnn- To enable the use of slow shutter speeds, particularly with high ISOs, to record the movement of subjects such as waterfalls, clouds or carsnn- To decrease depth of field by allowing the use of wider apertures, which helps to separate subjects from their backgroundnn- To reduce the effective ISO of high-sensitivity films (above 400 ISO) and allow their use outdoors in very bright situationsnn- To enable film and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other very bright scenes that could cause overexposure