Drop collisions (drop-on-drop)
We get quite a few questions asking about how to photograph drop-on-drop collisions such as those by Martin Waugh showcased on his Liquid Sculpture site and whether we have a kit for taking such photographs. The answer to the latter question is that we don't currently have a kit, although our photogate and delay unit can be used as part of a system for droplet detection and timing synchronization.
Here are some links to resources that may be helpful for setting up a drop-on-drop system.
Trevor Shannon's A Method and Apparatus for Easily Creating Liquid Splash Collisions is the most comprehensive reference we've seen for the do-it-yourselfer. Shannon describes the hardware, electronics, setup, and calibration procedures in detail.
Marcus Reugels has produce outstanding photos with his setup. See the links below.
Multi-Trigger
Wayne Fulton describes his set up using the Shako solenoid valve.
The following is an off-the-shelf kit. It also requires the Time Machine controller. Trevor Shannon (see link above) describes the use of the controller with his system.