I was taking a building structure with nice ambient light using high ISO without flash. The photo turned out as what I expected. However, when I took it with a person as foreground with Canon Speedlite as flash, the building structure at the background became too dark especially the ambient light became yellow. Any ideas how to take the person as foreground with the same lighting effect of the building as background as what I mentioned with good ambient light?
1) Photo (Photo 1.jpg) taken with nice ambient light without flash. f/2.8 1/40 21mm 0EV ISO 6400
2) Photo (Photo 2.jpg) taken with the same ambient light with a person and flash. f/2.8 1/40 20mm 0EV ISO 6400