Crab Filter, Premium Wide Reverse GND 0.75, 5.9 x 6.7 inches (150 x 170 mm), Reverse GND 0.75 specification (maximum ND6, 21/2 aperture).
Mainly when using ultra-wide angle lenses, such as sunrise, before and after sunset, the brightness difference between the middle and the ground, the gradual ND will allow you to connect your tonal more naturally. Depending on the lens you use, you can shoot the soft GND0.75 effect by upside down and down, but please note that the adjustment range is limited.