Many people remember this camera held by an enthusiastic uncle, blinding everyone during the holidays. If you look at pictures from that time, the subjects all have the look of surprise in their eyes. There was not a way to perfectly coordinate the flash with the shutter. The flash bulbs were very bright and burned for about ½ of a second to ensure the room was bright when shutter opened on the camera.
Before flash bulb technology was widely available in the late 1940s, flash powder was used. The camera operator would hold an open metal bowl with a mixture of magnesium powder and potassium chlorate. It was lit by hand and produced light similar to daylight. And was very dangerous.