Bursting Balloons !

Bursting Balloons !
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Monday, July 12, 2010

The Flash-bulb

Previously when I was taking high speed images of breaking light bulbs a few people mentioned that they would look better with a glowing filament .
Tonight I opened an older flash and un-soldered the wire from the capacitor to the flash tube and wired it in series with a 220 volt light bulb . The red wires and dotted red line show where it used to be connected .
When  I have the old flash on low output the flash fires weakly but there is no response from the filament .
When I switch it over to high power I get a reaction - but a little too much . I need to get the right amount of power to have the filament glowing without blowing out the exposure .


 More 'experiments ' to follow :)
 
15 minutes later and I had opened another older flash with thyristor control - in the hopes that I could get the flash to turn off sooner for a dimmer glow  . Not to be !
I faced the sensor toward a white surface to help it detect the flash and hopefully turn off quickly . It still gave out too much power .
At first I was confused as to why the optic flash trigger would not fire this flash but then I remembered that when I checked its trigger voltage it was "-8 v" , the earth pin was in the centre which was not normal - the electronics of the optic trigger could not switch a 'backward voltage' .




13/07/2010
Tonight I ran the wiring through a soldering iron as well to waste some of the energy . Now I have a controllable glow that will look right at iso200 and F16 .



This 'diagram' shows the path of the the current flowing through the circuit . The blue lines show where the wires were originally connected . The lower blue wire was cut and connected to the red clip going into the soldering iron . The current flows through the soldering iron and back down through the black clip which is connected to one of the terminals of the light bulb . The circuit is completed as it flows back from the other terminal and through the flash tube . Each item represents a volt drop of some sort and the coil of the soldering iron probably adds an inductance to slow things down a bit . The voltage drop across the light is just enough for a light glow and the rest of the energy is wasted in the soldering iron and across the flash tube .











17 July 2010 .
I bought some cheap light bulbs but unfortunately they only had frosted bulbs . I managed one ok shot with the one clear bulb I had .


and a few of the frosted bulbs ....




24 July 2010 .
I got hold of 10 clear light bulbs finally . I tried various 'devices' to destroy them and got some pretty decent results .




and a couple with the sword ....




And then I noticed my axe leaning up against the wall and decided to do a few with it .







Perhaps when I get exactly what I want I will spend some time processing the images to look better but I would really like to get it right in camera rather :)









2 comments:

  1. Not just for this post but in general, keep up the posting, and testing and crazy stunts with whatever you can lay your hands on.

    rgs,

    Matt

    ReplyDelete
  2. Don't encourage me :)I've already had a few threads removed on a forum !

    ReplyDelete