Using feathering for photo restoration
Photo restorations should be as natural and look untouched by human hand. This is where feather comes into play. The feather is how far an edge spreads. If you wanted to select an object and paste it into another image, the edge definition must match that of the master image. Feather enables you to do this with very fine adjustments ensuring the edges of your object are not too soft or out of focus and not too sharp, looking like they were cut with scissors.
Realism is the fundamental and most important part of photo restoration, without the feather we would be in a bit of a mess. It can also be used to blend skies and gradients.