Comment by dagmx

It’s not just about matching the frequency but also the phase.

This is easier when your lights are all in phase and also in a single frequency, but you might also have bulbs that are at different frequencies (120 vs 60) or electric hookups that go out of phase.

It’s a very tricky problem to solve and to the best of my knowledge, nobody truly has. Film lights do clever and expensive tricks to match phase but that’s not feasible in a domestic setup.