Originally posted by C.W Tsorotes Well my thought would be to just make the camera think its connected to a flash with HSS.
Perhaps an AF360/540 with a broken flash could be modified for such a purpose?
Yeah, you would need to somehow tap in after the pre-flash and then sync with one of the illumination flashes. You would not want to catch any metering or communication flashes and would need to wait or somehow determine when the first actual flash is started that is supposed to be seen by the sensor.
If you can cripple the 360/540 in some way or rig up something to catch the right signals, then you have something workable. You do need some sort of brains in the system that will talk to the camera and fool it somehow. Your idea of a broken PTTL flash is probably a good start. :-)
Wish I knew enough electronics. The concept actually seems simple enough. The HS flashes would be so minuscule that you would not even need to disable the PTTL flash after the first signal is caught... assuming you're signaling an external strobe of sufficient power.