Irix Edge 100mm Reverse Gradual ND Square Filter

A reverse graduated neutral density filter is built the opposite way round from a normal grad: the density peaks at the transition line and eases off towards the top of the frame. That matches what a sunrise or sunset actually does, where the brightest part of the sky sits just above the horizon rather than at the zenith.

These are 100 x 150 mm rectangles for the Irix Edge IFH-100 and IFH-100-PRO holders. The glass is toughened Super Resistant with Nano IR construction, multi-layer anti-reflective coatings and a double-sided NANO hydrophobic and oleophobic layer.