Edge Softness (appears in Lens)

The Edge Softness tool creates a circular, out-of-focus area with controllable falloff and on-screen adjustments of position and size.

Blur Size: Size of the blur operation itself.

Quality: Number of blur iterations. The default of 3 is equivalent to a standard Gaussian blur operation.

The following controls can be drag-adjusted in the Preview area:

Center: The center of the blur region (and the least blurred area), expressed as percentage offset from the image center.

Radius: Size of the area outside which the blur operation is at full strength.

Spread: Threshold/softening region feathers the radius.