@soundofsun @freemo If you have a photodiode with a fast enough response time and something you can use as an oscilloscope (probably a raspberry pi would be enough at the frequencies a human would be able to perceive), you could try to measure it.
@freemo @soundofsun True, though I assumed the leads aren't necessarily exposed on all of them.
Also, photodiode + raspberry pi could work without actually having an oscope with the proper probes.
@pganssle Fair point.
@soundofsun