[eno_]

A slave flash is a flash with a photocel that detects a flash and fires. It is used in photography to provide an additional angle of lighting. The benefit is that you don't have wires running all over to fire the flashguns.

There is no practically detectable delay in firing a slave flash - your eye, nor any still-image camera, could never see the "sequence" of flashes. It is just as closely synchronized as if it were a hardwired connection. So there is no way a traffic camera could avoid being temporarily blinded by a slave flash.

Someone fairly clever could build a flash bulb into a license plate light fixture, and cannibalize a cheap used slave flash for the other circuitry and photocel. The flash bulbs in those pocket digital cameras are very tiny, and would fit next to the ordinary license plate light.

[killjoy]

Someone fairly clever could build a flash bulb into a license plate light fixture, and cannibalize a cheap used slave flash for the other circuitry and photocel. The flash bulbs in those pocket digital cameras are very tiny, and would fit next to the ordinary license plate light.

Just get a Wein hot shoe slave and put it on an old flash. If you really want to get fancy, wire the flash so it is powered off the car's battery. A Wein hot shoe slave can be had for under $10. An old cheap flash can be bought on ebay for a few bucks more. If someone wanted to really get fancy they could hook up the slave sensor to some high output LEDs and mount it all into a license plate bracket.