Phones at raves are a contested topic. There is no universal rule, but there are reasonable defaults.

When it is fine

A quick shot of the lineup board, a photo of the room from the back wall, one selfie with your group at the bar. Take them, put the phone away, return to the dancefloor.

When it is not

Holding your phone up at the front of the dancefloor for the entire drop. Filming the headliner's face for two minutes at a stretch. Flash photography in any direction. These all earn you side-eye from heads and increasingly from venues.

The middle ground

The right pattern is: phone out for ten seconds maximum, phone away for the rest of the set. If a moment is good enough to film, it is good enough to actually experience without a screen between you and it.