Watching Deadwood reruns reminded me that before there were light bulbs photographers used some kind of powder that they would ignite somehow to create a bright “flash” of light.
What was the chemical that they used and is it still available? And how did they precisely time the ignition? Can someone point me to a webpage that describes the process?
Magnesium powder and potassium chlorate.
The little flash cubes/packs that you used to get for polaroid and 110 cameras used magnesium wire in a glass capsule.
You might have trouble purchasing these chemicals, as they can be used for… well… dangerous things.
If I recall correctly in my drunken condition (IIRCIMDC), it was powdered nitrocellulose, later with the addition of powdered aluminum. The same stuff is available in most good magic shops nowadays. (Less the aluminum.)
No cite. Sorry.
I never heard of nitrocellulose being used in this capacity – I always heard it was magnesium powder. But nitrocellulose would work very well. I used to work in a factory that made the stuff.
How was it ignited?
I have a camera with a flash pan. It takes a sheet of magnesium, which you clip to the top and bottom. When you’re ready to take the picture, you open up the shutter, stick a lit match through a hole in the back of the pan, wait for the paper to fully burn, then close the shutter.
I’ve never used it (don’t have any idea where you could get sheets of magnesium nowadays), but I have burned small strips of magnesium. If the sheets burned with the incredibly brightness the strips do, they must have been blinding.
Other materials such as zirconium and aluminum were also used. For instance, the once popular Philips flashbar used hafnium wool as its flash fuel.
Are you sure of it.? Of course, laws could be different in the USA (or in some US states) , but since magnesium powder is easily available here (I used to buy it in shop selling stuff for parties), I would assume it’s not generally speaking considered as highly dangerous stuff. Not anymore than fireworks, for instance.
Though I seriously burned my fingers once using it, out of sheer stupidity. Having forgotten to bring a detonator, I tested various stuff to make a “fuse”. In an ashtray. I warned everybody about the ashtray and kept it close to me in order to avoid any accident. Later on, I was told to come in a hurry to prepare whatever small “special effect” I had planned. I was smoking, and you can easily guess where I inadvertantly put out my cigarette.
I have a related question. In Deadwood, the guy taking all the photos (sorry the character’s name escapes me at the moment) was using the flash outside on a sunny day. Would it have been necessary on such a bright day? It just seems even in that time period that if it was used inside to provide adequate lighting and the shots came out satisfactory then wouldn’t they be a bit washed out if it was used when the subjects were standing facing the sun?
Perhaps the film itself wasn’t as sensitive in those days? Just a WAG…
Filll Flash!
The old gelatin emulsions on glass plates were rather insensitive, compared to today’s film. Where now, an “all-purpose” indoor-outdoor film might have a 400 ASA speed, those glass plates were in the neighborhood of 6. Without the flash, exposure times would be in the tens of seconds, even in sunlight.
As for synchronizing, there was little need. The photographer would open the shutter, ignite the flash, then close the shutter.
Cool! My friend and I managed to blind 
ourselves for a few minutes after setting off an entire one of those. (Through a sheet of paper no less). Now I know what that steel-wool looking stuff was. 
It was done for dramatic effect, not historical accuracy.
Yeah, gotpasswords has it exactly. Subjects had to hold still to avoid blurring.
Maybe not the magnesium, but the potassium chlorate - actually, you’d probably be able to buy it (as a weed killer, or more commonly, sodium chlorate), but it would probably contain a chemical fire suppresant; I kow this because I used to buy the stuff as one of the ingredients to make (highly dangerous) explosives as a teenager (no, I won’t post the recipe). When they started putting the fire suppressant in it, I was forced to stop (probably a good thing, overall).
A friend of mine used to do the same. Until he caused a fire at his parent’s (quickly put off, tough. Nothig serious). Well…I assume he was using the same product. I suppose (and hope) there aren’t dozens of weed killers that a teenager can turn into explosives…