We travel when we can and are mostly travel photographers. However, we are at home now and decided to take a photography class. One of our assignments required us to experiment with flash, so we decided to use sound-activated flash. Normally, sound triggers are pretty expensive. However, we found something called Trigger Trap that costs $47 at B&H (this isn’t an ad – we are just telling you what we used).
The Trigger Trap uses an iPad or iPhone application to detect sound and emit a sound via the headphone jack (sorry iPhone 7 users). We put the camera in bulb mode in a dark room and attached the trigger to an off-camera flash.
We then got an unbreakable plastic glass, filled it with colored water, and dropped it into a plastic pan. The sound of the glass hitting the pan triggered the flash. Everything was set on manual in the camera (including focus) and the flash was in manual mode to minimize shooting delays. We had a lot of trials and the photos below show some of the better results.
As an aside, we also tried using the Trigger Trap with an Android phone. It very rarely worked. A little Googling showed us that, when sending sound to the headphones, Android phones have a longer time lag than iPhones and iPads. Normally, this doesn’t make the slightest bit of difference, but it this case it caused us to miss too many shots.
We would include the photo specs for these images, but they don’t really mean much since the flash itself determined the exposure. With the flash at 1/8 power, we found that f/8 or f/9 was reasonable. A remote trigger was used to open the camera shutter and close it after dropping the glass. The shutter timing did not require any precision.