(^38) The Official Raspberry Pi Projects Book raspberrypi.org/magpi
PI FILM
estoring home movies
captured on film can be
a real challenge. Film
conversion is a time-consuming
and often expensive task.
One maker, Joe Herman, took
matters into his own hands by
hooking up a Raspberry Pi Camera
Module to an old projector.
Joe’s cousin and uncle uncovered
a box of 130 reels recorded by his
grandfather. Leo’s moves “dated
back to 1938,” says Joe.
The preservation of these
memories was important for Joe’s
large extended family. But to have
them professionally restored
would have cost “many thousands
of dollars.”
The obvious approach with
a project like this would be to
run the movie and record it using
a camcorder. The results from that
approach are very poor, though.
Professionals photograph one
still image at a time and then stitch
it all together, which is why the
process is so expensive.
Pi Film Capture is a smart
film transfer system that uses a
Raspberry Pi and Pi Camera Module
with Bell & Howell 8 mm and
Super 8 projectors, or an Ampro
Imperial 16 mm.
The setup employs a frame-by-
frame approach. The Raspberry Pi
takes a still photo of a film frame
and sends it to a remote client
computer for processing.
The Raspberry Pi is connected
to a stepper motor that moves
the frame to the next cell. It then
repeats the process until the
entire reel is captured. “Most old
projectors would work,” reckons
Joe. “They were built to last.”
Once the process is completed,
the result is a folder of images.
“I can combine these quickly into
a viewable movie using FFmpeg
(ffmpeg.org),” says Joe. If a
more sophisticated clean-up is
required, he uses a program called
AviSynth (avisynth.nl).
“A key design goal for me was
to use easily obtainable parts,”
reveals Joe. “Mostly because when
I began the project, I was unsure
whether it would go anywhere and
didn’t want to invest too much in
expensive equipment.”
Joe solved “endless” challenges
while designing Pi Film Capture.
Projects SHOWCASE
Expertly converting old film reels to digital video one frame at a time
five-minute A
film reel can
produce 4000
still images
8mm captures
need a 25 mm
focal length
magnifying lens
The projector
uses a NEMA
17 motor and a
DRV8825 chip
Joe 3D-printed
mounts for the
lamp and motor
It uses the
original 5MP
Pi Camera
Module
Quick
Facts
Placed inside the projector, the
Raspberry Pi Camera Module records
each image, one shot at a time
CAPTURE
A stepper motor (controlled by the
Raspberry Pi) is used to advance
the film reel one frame at a time
R
The Raspberry Pi is used to capture the
images from the projector and sends
them to a client computer for processing
JOE HERMAN
Joe is a tinkerer and
programmer with an
interest in film preservation.
vimeo.com/jphfilm