Feather the light, feathering
EN: Feather the light, feathering
To reduce the light level to near 0 at the edges of the beam; to pan or tilt the light so that its dim edge is used. Fixtures, such as fresnels, that are feathered by design are easy to overlap. Tip: The edge of the Beam on most fixtures produces the sharpest shadows.
Tiffan edu Glossary