Traditional Culture Encyclopedia - Photography major - What's the difference between Hou Lian synchronization and front screen synchronization in night scene shooting?

What's the difference between Hou Lian synchronization and front screen synchronization in night scene shooting?

Front curtain synchronization means that the front curtain is opened, the flash starts to illuminate the subject, and then the camera is exposed.

Hou Lian synchronization means that when the curtain is opened, the flash will not flash first, but wait until the moment before the Hou Lian is closed to complete the exposure.