The graduated filter tool simulates a real neutral density graduated filter. These can be used used in for example landscape photography to limit the brightness of the sky. It applies an exposure adjustment in the form of a gradient.
The strength of the filter, in stops.
The angle slider allows to rotate the direction in which gradient is applied.
The feather slider controls the width of the filter’s feather (gradient). At 0 there is no feathering, just a sharp edge which can be useful as a temporary setting when choosing position and angle of the filter. The slider value (0 - 100) specifies the width of the feather as percent of the image diagonal.
Center X and Center Y
The Center X and Center Y adjustments moves the center of the filter’s feather (ie the rotation anchor point) horizontally and vertically respectively.