Photojournal

Session 1

This session we acquired our tank, computer, and flash equipment.  We also obtained our oil and water, and learned how to use the gun, and the Multiplexer program.  We learned how to adjust the delays and times, as well as the sensor logic.  We connected the flashes, and powered up half of them for a test shot.  They were in front of the tank, and caused excessive glare.  We also found that water would form a jet and enter the barrel, altering the speed of the pellet.  We placed plastic over the tank to reduce this splashing.

Setup showing layered liquids and vertically mounted pellet gun.  The frame is visible, and the sound trigger is connected to the wire running behind the upper left part of the frame.

Session 2

We supplied batteries to the rest of the flashes, and bundled them in pairs to provide easy access to controls and battery panels.  We added color filters to the flashes to create a series of contrasting colors in our flashes.  We watched and labeled the sequence of flashes, but found that the second flash was not firing.

Photo taken with no oil to roughly align the pellet in the frame.  This one was late, and shows the bubbles formed, as well as previously used pellets and the glass plate used to stop them.  This is the best photo of the tank interior.

Session 3

The problem with the second flash in the sequence led to a delay in work until a solution could be found, as the problems seemed to be with the circuit within the optoisolator box or in the many wires connecting the flashes.  We had insufficient knowledge of these systems at this point to correct the fault.

Apple II+ as intervalometer with sensitivity controls for sound trigger and optoisolator flash control.

Session 4

We fairly well wasted the fourth session, experimenting with trial and error on the delay and interval of the flashes.  We could never obtain any reliable results, and failed to consistently photograph the pellet.  This remained a mystery to us.

Session 5

We simplified our flashes, going from twelve to eight.  This allowed for easier setup and analysis.  The inconsistencies, however, continued without any alteration to intervalometer settings.

Session 6

The source of the problem was found to be the mounting of the sound trigger directly to the gun frame, where vibrations could interfere.  By moving it to a shelf nearby, we were able to obtain analyzable photos.

Photograph of pellet in air, water, and oil.  The interface is demonstrating interesting formations after being shot repeatedly.