Comment by derefr

It’s not like these bulbs are flickering in a way you can perceive just by slowing it down by 2/3/4x. They’re flickering at 10000+ Hz. The reason cameras perceive the flicker is that they take discrete samples, with an (electronic or optical) shutter in between. This creates a beat frequency with things that also flicker, in effect “tuning into” a HF flicker and “lowering it” into the visible range, the same way a superheterodyne radio tunes into a HF carrier wave and brings it down into the audible range.