The synchronizer 1, wherein the flash unit operates according to a flash sequence in a flash interval after actuation of the actuator, the fundus camera configured to coupled to a digital camera system including an auxiliary power supply and {HEAD ~ a shutter system} having {TAIL ~ a digital camera shutter} having an associated open position in a transit time consistent with the flash interval to capturing an image at the digital camera system, the circuit further comprising: 
having
The synchronizer 1 , wherein the flash unit operates according to a flash sequence in a flash interval after actuation of the actuator , the fundus camera configured to coupled to a digital camera system including an auxiliary power supply and { HEAD ~ a shutter system } having { TAIL ~ a digital camera shutter } having an associated open position in a transit time consistent with the flash interval to capturing an image at the digital camera system , the circuit further comprising :
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH