High Speed Photography Flash Trigger by Sound or Laser Barrier (Arduino)

Introduction
High-speed photography can be a game of trial and (much) error. When I started experimenting, I would repeat the same action (breaking bottles / popping balloons / dropping objects in water / …) while my camera was on burst mode. Shooting at 7 frames per second sometimes gave me a few usable results, but it was hard to repeat and be consistent. At the end of a session, you end up with hundreds of pictures you have to sift through…
That’s why I bought an Arduino to help me get the timing right. In this instructable (my first!) I will show you how to build an Arduino based flash trigger for high speed photography. The trigger can be activated by sound, vibration or by breaking a laser beam.
This build is not easy but the end result is worth it. You can buy similar systems but they will set you back hundreds if not thousands of euros / dollars. I found that this approach taught me something and gives me more options for customising and adding features, not to mention more money in the bank!
In high speed photography, you want to open the shutter of your DSLR camera (or another type of camera with full manual control which will accept a remote cable) in a pitch black room and trigger the flash at the exact moment the action you want to capture is happening. As the room is pitch black, the sensor will only capture light when the flash is fired for a few milliseconds, thus freezing the action perfectly.
Some examples of the applications I have used this setup for are:
shooting beer or soda cans with a pellet gun and catching the explosion ()water drop photography paint dancing on a subwooferOther ideas I have yet to do:_
_catching a bird in mid-air as it comes in to land catching a picture of lightning …
funny story: did you know that when you are aiming your pellet gun to shoot full soda or beer cans you are directly in the spray line of said soda or beer? Turns out my buddy didn’t know that and he got covered in beer from head to toe…

I’m entering this Instructable in the Arduino Competition, so please vote for me if you made this or if you liked the Instructable! Thanks!
Disclaimer: A flash gun uses very high voltages to flash. It’s necessary to isolate this from your circuit or it could damage your Arduino or even worse, your expensive camera! You always do this on your own risk! I will not accept any liability or claims.
Warning: Working with lasers is dangerous to your eyes! Never look into the laser beam!”

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