Athabasca Square Filter ARK II GND64 system 100 allowing photographer to make gradual adjustment on his photo by adjusting the filter vertically via Athabasca A3 Holder. This GND64 also known as GND 1.8 Stop.
Athabasca Square Filter ARK II GND64 system 100 specification: Material : Glass Glass Type : Schott B270 Thickness : 2mm Size : 150 * 100 mm Coating : Double Side