Nikon SB-5000 Reference Manual page 69

Effective flash output distance range in non-TTL auto flash
mode
The effective flash output distance
range is indicated by numbers and a bar
chart on the LCD.
• The actual flash-to-subject distance
should be within the range displayed.
• The range varies depending on
the camera's image area setting,
illumination pattern, ISO sensitivity,
zoom head position and aperture.
C
C-12