I had been eagerly wanting to do this for quite sometime... and this weekend was it!
The first thought that might come to interested beginner photographers would be that this was shot at a very high camera shutter speed. But actually the camera was at a slow shutter speed of 2.5 secs in a very darkened room with a black background. The image was exposed with an off-camera flash (Canon 430EX II). So the image was captured with the fast duration of the illumination by the flash. The exposure duration by the flash was approximately 1/15000 sec i.e. the flash fired light into the scene for a duration of 1/15000 sec. The flash was set at 1/64th power and as per available information by various third party tests at that power the flash duration is 1/15000 secs. The duration becomes longer at higher powers. The reason the camera was put on a slow shutter speed was to get enough time within that duration to move and burst the water-filled balloon! And of course, use manual focus to pre-focus the camera at the balloon before the final action.
And now the question of the timing! Well there is a very simple yet very effective phone app based contraption called 'triggertrap' (www.triggertrap.com) which can be used to trigger the flash or camera by sound through your smartphone. So the flash was triggered by the sound of the bursting balloon catching the exposure at that exact moment! The triggertrap can be used for many more interesting creative applications like time-lapse, motion detection etc.
Camera: Canon EOS 60D, Lens: Sigma 17-50mm f/2.8 EX DC OS HSM FLD
ISO: 100, Shutter Speed: 2.5s, Aperture: f/11, Flash: Canon 430EX II at 1/64th power
