Roll Light rotates the light about its own line of sight (the light's local Z axis).

Rolling a light
Although Roll does change the light view, it affects the light object only if the light casts a rectangular beam or is a projector.
Drag the mouse horizontally to roll a target light or rotate a free light about its local Z axis.
This button replaces the Zoom Extents button when a light viewport is active.
Procedures
To roll a light:
- Activate a Light viewport.
- Click
(Roll Light).
The button highlights when it is on.
- Drag horizontally to roll the view.
- Press Esc or right-click to turn off the button.