If you watch the following music video, notice what happens to the high bay fixtures.


Here is the video:

https://youtu.be/mk48xRzuNvA

I say they're either CFL or LED .

They seem to have a bit of a fade out when switching off. Might have been wired for high wattage incandescent for the purpose of flashing them like that. Reason why I said incandescent instead of LED is that the video is from 2012, before screw in LEDs with enough light output were common.

That being said instant restrike HID lamps and ballasts do exist, they just use a higher voltage ignitor to allow for instant restrikes.

They seem to have a bit of a fade out when switching off. Might have been wired for high wattage incandescent for the purpose of flashing them like that. Reason why I said incandescent instead of LED is that the video is from 2012, before screw in LEDs with enough light output were common.

That being said instant restrike HID lamps and ballasts do exist, they just use a higher voltage ignitor to allow for instant restrikes.

It's weird to think that this wasn't that long ago (ok, 8 years is a while) but back then, high wattage incandescent would have been the most likely option here.

There are HID ballasts with an "arc keeper" feature: A battery (or a supercap) backup HF generator maintaining at least some discharge (very low current, just barely maintaining the ionization) within the arc tube during the brief power outage, so the arc can then restrike instantly once the main power is restored.
In "pre-LED" it was offered as an alternative to the "backup halogen" capsule.

They are probably LED or CFL, but not HID. The fade in the turn on and off is probably caused by the big smoothing capacitors of the power supplies.