Aussi simple que la lumière
The pinhole version of this photo. Pinhole night photography is a mildly tricky business. The best times are usually at the shoulders of the day, when the sky is fading out to blue or fading in from night. Except this span of time lasts for only 30 minutes or so, and you lose a stop of light roughly every five minutes during twilight. So a pinhole photographer is in a position where they lose light faster than their cameras pick it up.
But as always, where there is a will there is a way. Or maybe more appropriately; where there is light there is a way.