Sony HDS-7100 User Manual page 114

Changing the manner of superimposition of the moving video
and freeze frames (afterimages) – F5 (PRIORITY)
Press F5 (PRIORITY).
Pressing this button toggles the settings "Over" and "Under",
changing the manner of superimposition.
Over: the moving video is on top.
Under: the moving video is underneath.
Chapter 5 Special Effects Operations
5-33