American Cinematographer - February 1985 - 96

The

of conventional pickup tubes) was well
suited to this task because the CCD is

Sony Super

Motion system
consists of a
camera,

sensitive
loss and

enough to deal with the light
by its very nature is not sub¬
ject to the lag or smearing associated
with pickup tubes. The dynamic resolu¬
tion (or sharpness of moving objects) is
much greater with a CCD image than
with the image from a pickup tube.
With a shutter restricting the exposure
time to 1/500 of a second (as opposed
to the 1/30 or 1/60 of a second nor¬
mally represented by a video frame or
field), it becomes possible to see the
stitching on the baseball when a pitch is
re-played in slow motion. The ball still
appears to jump from one position to
the next on its way towards the plate,
but it is distinct in each position and it
is possible to see how it is rotating.
Another company which has
been modifying cameras to incorporate
shutters is Nisus Video Inc. They began

recorder,

operational control
wit, digital
processor

unit and

supply unit
with the possibility
of adding a remote
control panel for the
operational control
lower

unit.

is

generally

device which converts
digital signal, stores it
momentarily and then converts it back
into an analog signal in a way that
insures that it is no longer distorted by
variations in the playback speed of the
videotape recorder. Since time base cor¬
rectors were required anyway to make
type C recorders completely feasible for
production and broadcast work, it was a
relatively simple matter to obtain slow
motion by slowing down the tape speed
on a type C recorder. Since the drum
continues to spin at its normal rate, the
recorder puts out 30 frames of video
tor

a

each frame into

a

each second, but the content of the
frames depends on how fast the tape

past the drum.
There is, however, a marked
difference between the slow motion ob¬
moves

The lUisus N-3 is

tained this way and
obtained by running a

the slow motion
film camera faster
than 24fps. What a type C recorder
creates is comparable to the kind of
slow motion effect created by optically
repeating frames from a conventional
24fps shot. What you see in conven¬
tional slow motion from a type C re¬
corder is motion in which a fast moving
object may be blurred and/or jump from
one position to another instead of mov¬
ing fluidly. The videoese term for this
jumping motion is "judder." (Presum¬
ably "judder" is derived from jitter and
shudder?)
its

CCD

the

blurring of fast moving objects. The
camera (a camera employing solid
state "charge coupled devices" instead
CCD

a

modified Sony
camera with a rotary
focal plane shutter

capable of speeds
from 1/500 to

1/10,000 of a
second. It is used in

conjunction with

RCA's shuttered version of
attacks the problem of

camera

a

conventional
recorder.

with video cameras used for instrumen¬
tation work for the military and are now

offering for sale a modified Sony camera
which they call the N-3. The N-3 has a
continuously variable shutter which can
be set for exposures ranging from
1/500 to 1/10,000 of a second. Tests
shot by Nisus indicate that shutter
speeds of 1/3,000 of a second or faster
produce the best results in slow motion
playback of fast sports events like div¬
ing or gymnastics. They expect to have
a similarly modified Ikegami 79E avail¬
able this year.
The Super Slo Mo system
ABC used for the Olympics is called

Super Motion by Sony. Sony was com¬
missioned to design the system with
the primary objective being the reduc¬
tion or elimination of "judder" rather
than blurring. To achieve this Sony
adapted techniques from its high defini¬
tion video system to create a special
super motion camera, optical fiber
transmission system and recorder. One
of the requirements from ABC was that
the slow motion images should be re¬
corded in such a way that the tape
could be played back on any conven¬
tional type C recorder.
To accomplish this Sony de¬
signed the recorder to run three times
normal tape speed during the recording
and the camera to generate complete
frames of video at a rate of 90fps
instead of 30. When the tape is played
back at normal speed on the same or

94

American

Cinematographer

March 1985
American Cinematographer - February 1985

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