Nikon Speedlight SB-16 Instruction Manual page 19

After you take the shot, watch the
ready-light inside the camera 's view-
finder or the one on the 88 -16. After
a short while , it will light up again to
tell you the flash unit is recycled and
ready to fire for the next shot.
Note :
If
the flash unit fired at its maximum
output, the ready-light blinks as a warning im -
medialely following the shot to indica te there
still may be underexposure. In this case. check
the combination of shooting distance and
aperture setected. and use a wider aperture or
move closer to the subject If necessary. This
warning is also provided in the viewfinder of all
Nikon ca meras having a built -in ready-light
(except F2-series cameras).
20.
Turn off the flash unit.
To conserve battery power
between shooting sessions , slide the
power switch to the left.
19