Sometimes laser/light sensor can not be used, for example, for saucers and fin-less rockets.
Plan B: touch sensor.
The touch sensor uses adhesive copper tape that attaches to rocket fin or body. Copper tape serves as conductor between two paper clips, which are shaped to loosely sit on the fin. Paperclips connect to the CameraAxe with alligator clips and extension wires.
Upon lift-off, the rocket pulls the tape, paper clips, and wires up. Wire tension pulls paper clips off the fin, while the copper tape remains with the rocket. The circuit disconnects, and this triggers camera.
Note on safety
The wire leading to CameraAxe has fail-safe connector. In the event the paper clips get “stuck” on the fin, accelerating rocket will pull the wire out of the failsafe connector.
From rocket guidance perspective, touch sensor will not alter the rocket’s path as the rocket is still guided by launch rod or rail.