On Thu, 22 Jan 2004, Mark Roberts wrote: > Tom "William Tell" Reese wrote: > >I've been thinking about trying some low tech "bullet through apple" > >photography. I'm still puzzling through a trigger mechanism to trip the > >shutter and get the flash to fire. Has anyone tried those light beam > >triggers? How wide is the trip beam? Would a bullet break the beam enough to > >trip the shutter? Does anyone have any ideas for a lower cost trigger? > > The way these have been done in the past is with an acoustic trigger. > The sound of the gun is picked up by a microphone which is used to > trigger the strobe. The distance between the gun and the microphone > determines the delay between the firing of the bullet and the triggering > of the strobe. (Sound travels at ~300 meters per second.)
An article about building a low cost "bullet through apple" photography system was published to slashdot today. http://web.mit.edu/Damonv/Public/Doombolt/ This has details on how they did it. Their system has a photosensor near the end of the muzzle that watchs a piece of paper. When the bullet (a bolt in this case) goes past it disrupts the paper which triggers their flash. The camera is left on a long exposure during the whole time and the photography is done in a dark room to avoid any shutter lag. Their results are impressive for a fast garage setup. alex
