Wednesday, 27 July 2011
10 stop ND Filter
Some time ago I purchased a 10 stop Neutral Density filter from Lee Systems. It is a 100mmx100mm plastic filter that has a density equivalent to approximately 10 stops. The purpose of this filter is to allow long exposures during daylight photography, thus showing movement to a degree not possible just by stopping down and using a slow IS0. The photograph below was taken on a 5x4 camera with Delta 100 film. 3mins at f11 has given the water plenty of time to show the movement, although when there are highlights it is possible the DR will exceed the film and the white burn out. Camera movement must of course be zero, even to the extent that standing still beside the tripod is essential, as any small vibration could induce movement. This example is a horizontal crop from a vertical shot. The water in the bottom half had burned out and no amount of work while scanning could find a texture in the white. This subject is of course a bit "old hat" but for experimentation has served the purpose.