This filter is made using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch. This filter measures 4 x 4″ / 101.6 x 101.6mm.
Does not affect coloration of the image and is ideal for use with other filters.
0.3 provides a 1 stop exposure reduction
0.6 provides a 2 stop exposure reduction
0.9 provides a 3 stop exposure reduction