this position, before, i wanted to take startrails only, but when i played the preview of last photo, i found the galaxy was in the photo, then i know it, i can play time lapse video by those 350 pitures.
My camera setting is:
5D3 + 24 f1.4LII
ISO 400, f1.8, 20s exposure
around 340 photos ( 2 hours approximate)