Remote photo flash light-activated trigger

Thread Starter


Joined Oct 22, 2004
Surfing the net I have found several circuits to do this. I want to trigger 3-4 electronic flashes (in addition to the one on-camera). Each remote flashwould have its own.

Bought commercially, these would run up quite a bill. The build-it-myself designs still use a handful of components but would be acceptable.

Before I follow up I did find a reference (no schematic, no other description) that suggested a lascr would do it and a lot fewer components would be required.
Sounds great.

I know what a lascr is but have no idea how to create a functional circuit.

Please, can anyone suggest a circuit? Nothing fancy but a sensitivity control (to prevent firing by ambient room lighting) would be a plus.

Thank you.


Joined Jan 22, 2004

am not sure if by using a laser activator would entail lesser parts than the usual IR tx/rx circuit. and besides it's more costly. :(


Joined Apr 20, 2004

If you have a photoflash unit available, you might be able to do some reverse engineering. The lascr should approximate the function of the manual pushbutton.

I don't think ambient light will be much of a problem - at least not is you need flash. The trigger will be the "factory" flash unit, and the brillance and sharp onset should allow accurate lascr operation. You can always set up a test circuit to see if this assumption is correct. The lascr will remain latched on with DC applied. Set one up with a battery and led, such that the led will illuminater if the lascr is triggered. See if things work the way you want.