hrun

I've been having a bit of a debate about this photo: http://commons.wikim...,_1901-1902.JPG

The consensus was that it's a staged publicity shot for a real act, but the debate shifted into whether it would have been possible to take the shot for real in 1903.

I've suggested that the photo could have been taken using an open shutter, illuminated by confined charges of flash powder to speed up the burn, triggered simultaneously using the old fulminate caps and electric blasting machine more commonly used for dynamite.

I've been completely unable to find any references to people using confined flash for high-speed photography. How bright and how short a flash can you get out of flash powder, especially if you drive it with a detonator?

Hello everyone! New member, not a professional or even hobbiest pyrotechnician, but hoping I can get an answer to a pyro question.

In the movie The Abyss, Bud lights a flare during his long underwater descent, after his lamps implode from pressure. (I'm referrring to the pyrotechnic flare while he's still falling, not the cyalume light stick he uses when he reached the bottom.) Underwater flares have apparently been used in other movies:

http://www.mail-arch...m/msg00106.html

and I've found a mention that Cousteau used underwater flares during cave dives:

http://www.bec-cave....p;limitstart=14

Underwater flares don't seem to be available any more, Pains Wessex certainly don't seem to advertise them, so I was wondering where the movie makers get theirs from, and how they work?

I'm quite aware that a flare composition will contain its own oxidiser, I was more concerned with the mechanism for overcoming the heat losses to the water. It occurred to me that a composition that gave gaseous combustion products could generate its own "gas shield" for the burning flare. Alternatively, a very high energy composition might simly maintain a steam layer and so reduce the heat transfer rate. Both of these could be expected to be less effective as the pressure increased with depth.