🚀 go-pugleaf

In article <144@snaring.UUCP> steve@alberta.UUCP (Steve Sutphen) writes:
>find such a device.  I have two projects that I would like this data for:
>upgrading the flash level in a friends slide duplicator, and building some
>experiments to try and freeze moving objects on film.  I want to understand

>               steve.


Not flash tubes but here is some info about my efforts at
motion freezing by flash.

A few years ago I set up a system which used a microphone, an
amp, an AppleII and an opto-coupled triac to fire a flashgun on
a sound trigger.  Various microphones were tried, the ones they
sell in Tandy for recording phone call are useful for some
purposes, it depended on the shot which one was most suitable.
The amp was actually a cassete deck in record-pause-monitor
mode with the monitor line plugged into the cassette port of
the Apple.  A dozen or so lines of 6502 code read the port
until a sound was detected then went through a delay cycle and
fired the flash by sending a signal to the triac via the
game-paddle socket.  The delay was set by the Basic calling
program and could be from 28micro sec to ~0.75 sec.

I got some pretty good results, well I thought so anyway, my
favourite being a lightbulb dropped onto an old piston and
totally crazed yet still retaining most of its shape.  You can
use the technique for watersplash photos, dart in balloon shots
etc.

Well worth a try but make sure you keep all those nasty big
voltages in the flash well separate from you computer.

Cheers, Dave.

Dave Edmondson                  davide@uk.ac.qmc.cs
Dept. Comp. Sci.                davide@qmc-cs.uucp
Queen Mary College
Mile End Road
London E1 4NS
01-975 5250