Nikon SB-5000 AF Speedlight Reference Manual - English - Page 127

Remote flash unit Flash-ready AF-assist indicator illuminator Lights up Flashes slowly Lights up Flashes slowly or does not light up or flash at all Sound monitor 1 long beep 2 short beeps Flashes Flashes quickly for quickly for approx. 3 s approx. 3 s 8 long beeps Lights up Flashes quickly for approx. 6 s 12 long beeps in 2 different tones LCD panel - - - Status Ready to fire Fired properly Underexposure due to insufficient flash output may have occurred. To compensate, use a wider aperture (smaller f-number) or higher ISO sensitivity, or move the flash unit closer to the subject and reshoot. The remote flash unit light sensor has failed to receive the command. D With optical control, this is because the light sensor cannot detect when to stop firing in sync with the master flash unit, either due to a reflection from the remote flash unit itself or light from another remote flash unit that may have entered the light sensor window. Change the direction or position of the remote flash unit and reshoot. Wireless Multiple Flash-unit Photography D-47