You can set the following preferences in the Animation sub-category of the Display preferences in the Preferences window. (There are also Animation preferences in the Settings category. See Animation (Settings) preferences.)
Ghosts
Steps before current frame
Specifies how many ghosted images are drawn at frames before the current frame. The default is 3.
Steps after current frame
Specifies how many ghosted images are drawn at frames after the current frame. The default is 3.
Frames per step
Specifies the number of frames between drawing the ghosts. The default is 1.
