In Part 1, I showed my setup for taking water droplet photos by using an eyedropper and an IR emitter/receiver pair. After learning from that setup, I created a fully-automated droplet setup which opens the camera shutters, dispenses droplets, and fires the flashes at the appropriate moment.
Once its all setup, a button push triggers the entire sequence:
With this setup, the consistency is very good. This is what 40 consecutive shots looks like in my photo editor:
Even the mid-air collisions are quite repeatable. Here is an example of nine shots taken in a row:
And here are some of our favorite photos:
As a final experiment before dismantling everything, we programmed the controller to run in a loop and increase the delay between dispensing a droplet and firing the flash by a few milliseconds per image. After a couple of hours, we ended up with the following movie made up of ~250 individual droplets:
Note: A big thanks to Aron Chavez who collaborated with me on much of this project and provided some of the camera equipment. You can see some more droplet photos and some of the rest of his work at his website, aron.design.