We don’t think this one is going to bring back the days of one-time-use flash bulbs. But for camera enthusiasts who do have old flash units lying around this will be quite interesting. [Sven] worked out a method of interfacing this vintage flash with a modern camera.
The trick is to map the trigger signal from the camera to the flash module. Instead of patching into an electrical signal from the camera he’s using the light from the stock flash. He cut an optocoupler in half, keeping the receiving side of the part. This is molded in plastic that was shaped to surround the original flash unit. When that flash goes off the triac in the remaining half of the IC is activated. This is connected to a hot shoe mounted on an extension arm that is attached to the camera’s tripod mount. The shoe can be used to interface a few different styles of flash modules.
We don’t have an alternative use in mind right now. But chopping an optocoupler in half could come in handy for other applications that use a bright light as a trigger event.