American Cinematographer - October 1968 - 44

AN AL TERNA WE EDITING SYSTEM
For the 16mm film-maker who can't afford
the real thing-a creditable substitute
set-up to aid in cutting sync-sound film
By

SPENCER

NELSON

Anyone who edits film may be in¬
terested in the mechanical 16mm sys¬
tem I use. It is simple and economical.
It is easy to operate. It affords a
speed-up of the editing process. It
has tremendous versatility. I dare say
it may, in certain ways, even compare
favorably with the well-known "movi¬
ola," the industry standard manufac¬
tured by the Magnasync/Moviola Cor¬
poration.
The Fundamentals
The system consists basically of two
differential rewinds, a motor driven
synchronizer with soundheads attach¬
ed, an amplifier, and a viewer (FIG¬
URE 1).
The differential rewinds are the key
to the system's success. Among other
things, they enable the picture and
as many as three related sound tracks
to be edited simultaneously with ease.
You will recall that, with a standard
hand rewind designed to run several
tracks through a synchronizer, several
reels and spacers are clamped onto a
long single shaft. This presents two
problems: First, it is frequently nec¬
essary to stop rewinding and take up
slack on one or more of the take-up
reels, due to diameter changes of film
build-up. Secondly, if one of the feed

or take-up reels is to be removed, it
may be necessary to first remove one
or more of the outside reels on the
shaft.
The differential rewinds eliminate
these two nuisances. The rewinds are
characterized by four separate spin¬
dles driven by differential gears
(FIGURE 2). The gears distribute the
torque in such a way that no matter
what the diameter of the feed and
take-up reels may be, slack will al¬
ways be taken up automatically. It is
possible to run a 100' spool alongside
an 800' spool, without having to stop
and take up slack. (It is advised, how¬
ever, to standardize on 800' reels). It
is possible to hold one reel still, while
an adjoining reel spins rapidly. It is
also possible to lock some or all of
the spindles together so that they turn
at the same speed, regardless of
torque load, so that editing can be
limited not only to four, but to three,
two, or one track as well.
Because the spindles are separate,
any one reel can be removed without
removing another.
Synchronizer Also Plays Key Role
Another important element of the
system is the motor driven synchro¬
nizer, which is actually an ordinary

(LEFT) FIGURE 1-An over-all view of the alternative editing system, which consists, basically,
of two differential rewinds, a motor-driven synchronizer with soundheads attached, an amplifier
and a viewer. (RIGHT) FIGURE 2-Individually driven rewind spindles insure that slack will be
taken up immediately, no matter what the diameter of the feed and takeup reels may be.

synchronizer with motor and soundheads attached (FIGURE 3). When the
motor is not in operation, the syn¬
chronizer is free wheeling. But when a
lever is flipped, the motor is turned on
and at the same time a clutch en¬
gages the synchronizer shaft so that
it runs at 24 frames per second in a
forward direction. If it is necessary to
stop instantly at a specific point, all
the editor need do is apply instant
resistance to the feed rewinder han¬
dle. The frame number on the syn¬
chronizer is mentally noted, and the
motor switched off. The clutch is de¬
signed to "give," so that no harm is
done to machine or film.
The magnetic sound heads can be
lifted off the sound tracks for marking
or rapid rewinding. The entire mag¬
netic head assemblies can be easily
removed with a screwdriver when they
might be in the way, as when con¬
forming originals. Before amplifica¬
tion, the sound is fed into a small mix¬
ing box with three potentiometers, also
mounted on the synchronizer. It is thus
possible to turn down the level of the
music track, say, while you hear the
narration. I would recommend that at
least two of the "pots" in turn be con¬
nected to foot pedals so that, while
the editor's arms are busy turning the
rewinds, he can get a rough idea of
how the film would sound in a mix by
adjusting the music and dialogue vol¬
umes with his feet.
The viewer (I use a Moviscop) is
set best with the picture 40 frames
in advance of the sound. This pre¬
sents no problems. The picture track
is simply edge numbered 40 frames
(one foot) in advance, so that picture
and sound will be in sync when the
numbers are aligned in the synchro¬
nizer. There are two methods of mark¬
ing a frame: One is to use the viewer's
(ABOUT THE AUTHOR: Spencer Nelson stud¬
ied motion picture production at the University
of

Southern

California.

He then

worked two

years for a small educational film production
company in Boulder, Colorado. Early in 1965
he formed his own company, Spencer Nelson
Film Productions, and has since been making
films for institutions and industrial concerns.)

760

AMERICAN CINEMATOGRAPHER, OCTOBER 1968

American Cinematographer - October 1968

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