From the Adorama YouTube Channel:
Feathering a light is so much more than simply turning it away from your subject. In this video photographer, Gavin Hoey takes you through why feathering light is an essential studio lighting skill and how he uses it to control light in his small home studio.
Although the most common way to feather a light is to move it horizontally, Gavin also shows you how vertical feathering can open up more lighting options. He also bursts a popular portrait myth that feathering a light will give a softer light.