FOR A SPIN
TIME AND MOTION STUDIES
Just like the movies, the Autophenakistoscope
works best in low light. Dim the lights and plug it in.
It first spins up the motor to half power, flashes the
LED a few times, then starts reading inputs from
the potentiometers. When the motor pot is turned
all the way down, the motor should be off. When
the strobe pot is all the way down, it should flash
about once per second (1Hz).
Adjust the motor and the flash frequency to a
moderate level. Toggle the mode switch once or
twice to figure out which is which — in automatic
mode, the image should stabilize; in manual mode,
it will wander or not be legible.
It’s time to experiment. Adjust the knobs and
you’ll see that multiple frequency combinations can
produce smooth moving images. It’s also possible
to freeze the image by adjusting the rotational
frequency to match the strobe frequency.
When I first built this project, I noticed that the
image can “roll” just like it used to on the old black-and-white TV when I was a kid. It turns out that
this is a completely analogous result.
Another interesting experiment is to videotape
the Autophenakistoscope. You’ll find that the
frequencies of the strobe can coincide with the
scanning frequency of your recorder. If you get it
just right, the scope will appear to be dark in your
video when it looks well-lit to your eyes.
DESIGN YOUR OWN IMAGE DISKS
To generate the sample image disks at makezine.
com/20/autophena, I took some vintage animation
loops and cleaned them up using GIMP software
( gimp.org). To make the process easier, I wrote a
web application, linked from the same web page,
that you can use to make ’scope-ready disks from
I discovered the phenakistoscope while investigating
mechanical television. Mechanical television is
actually very simple, but impractical except for very
small screens. The scan lines are generated with a
perforated spinning disk known as a Nipkow disk.
In the 1920s, television started with 24- or 32-
line screens, and there were regular mechanical
television broadcasts decades before Milton Berle
showed his face in our (grandparents’) living rooms.
A 420-line spinning disk is another story; it would
have to spin at very high frequencies to fully paint
the screen at a rate that would satisfy the eye.
But the Autophenakistoscope would make a great
platform for a modern, experimental mechanical
television. I’d also like to see it scaled up.
For videos of the Autophenakistoscope in
action, along with project templates, sample
image disks, code, and a web application that
generates custom image disks, see makezine.com/
Grab a special image disk from project illustrator
Rob Nance at makezine.com/20/autophena.