|Image by Zarek Tuszynski from Wikipedia|
Many readers might be too old to remember these things, but when I first took photos as a boy we still used them. The bulb typically contains a magnesium filament, which burns out in a moment of glory. As it goes, it heats up the glass casing so much that it causes that familiar crunchy sound effect.
So far, so good. But romantic though these old devices seem, they had one big problem - they were one shot (apart from the short-lived flashcubes etc., which were too small to be used by anyone but amateurs). So with a pro flashgun like the one in the image, the photographer had to get a handkerchief or something similar with which to remove the red-hot bulb, put the old bulb somewhere safe and insert a new bulb - a process that inevitably took several seconds.
What I don't understand is why the TV and movie people, who put so much effort into making sure period clothes etc. look absolutely perfect, always mess up on science and technology. Take last night's Maigret. A suspect arrives at the police station, pulled through the midst of a small crowd of journalists, of whom maybe four or five are photographers. In the time the person takes to get through them - maybe three or four seconds - a battery of about 20 flashes goes off. So where are they all coming from? No one changes bulbs. No one has time to change bulbs. It's just carelessness.