American Cinematographer - July 1983 - 48

tion it

necessary to deal with

was

B&W

Video Assist
By ED DiGIULIO
Stereographies Corporation, lo¬
cated in San Rafael, California, has

developed a unique and extremely ef¬
fective 3-D video system which is
compatible with specially modified
standard monitors.

Filming 3-D is similar in many ways
special effects work, such as
shooting miniatures. The director of
photography never knows how suc¬
cessful the desired effect really was
to

until he

sees

the dailies. The 3-D

video viewfinder is, in fact, an invalu¬
able aid to the director and the direc¬
tor of

photography because it permits

them to

see

how the actual shot will

work without

having to wait for

dailies.
There are so many variables in 3-D
cinematography, such as inter-ocular
spacing, convergence and parallax,
that even an expert cannot be abso¬
lutely certain that a given shot will
work as well as he expected. With the
3-D video viewfinder, the director of

photograghy and the director are
looking at the images displayed on a
monitor exactly as they will be super¬
imposed on the theater screen. Even
without glasses, they can observe
whether there is any vertical parallax
in their scene (which would mean that
their lenses are not properly aligned
vertically). They can also see the
amount of stereo separation that is
being achieved, and, knowing the
monitor width and the ultimate pro¬

jected screen size, they can easily
calculate if the separation exceeds
limits that they know to be practical.
With the glasses on, of course, they

the shot

it will

actually ap¬
pear on the screen, and the full 3-D
effect will work (or not work) on the
monitor exactly as it would on the
can see

as

screen.

For the purposes

tion, the film

cameras

of this applica¬
used for shoot¬

ing 3-D have a video camera optically
coupled (or tapped) into their viewing
optics so that the video camera sees
the ground glass image exactly as it is
being recorded on film. The 3-D film¬
ing system can be either a single cam¬
era with dual lenses
recording a socalled "over and under'' format (i.e.,
the upper half of the frame is the left
eye image, and the lower half is the
righ eye image), or it can be two cam¬
eras set at right angles with a partial
mirror in between them. If a single film
with dual lenses is used, the

images because the video cam
eras "tapped" to the
viewing optic?
of film cameras are typically B&V\
video cameras. However, the systerr
works equally well with full color im

ages. We have several demo tapes
that can be played on a standard U
matic recorder. When the output

sig

nal from the recorder is fed into the 3
D encoder box and subsequently to £

specially modified full color monitor
using the special elec¬
tronically shuttered glasses can see
the viewer

3-D in full color.
For live

applications, two videc
directly view the ac¬

would

cameras

tion in the same
cameras

manner

that two film

would otherwise be used. Ir

the case of compact

however, either B&W
cameras

such

as

video

cameras,

one-gun color
the Sony camera,
or

they could be mounted side-by-side
with convergence being accom¬
plished by the angling of one of the
cameras. Here again, the output ol
the

two

would

cameras

be fed

video tap camera will be

through the 3-D encoder box to the
specially modified monitor where ful

two

color 3-D could be viewed with the

camera

viewing the
images and relaying them to our
special 3-D encoder box. If two cam¬
eras are used, the video
signal from
the two video

special electronically shuttered
glasses.
We have demonstrated this

tap cameras-one in

each film camera-would also be

re¬

layed to our 3-D encoder box.
The signal from the 3-D video en¬
coder box is fed to a specially modi¬
fied B&W TV monitor. Special goggles
that have electronically shuttered ele¬
ments are plugged into the 3-D en¬
coder box. It should be noted that the

glasses are being switched from a
transparent to an opaque state: they
are not polarized. For this reason, the
head may be tilted at any angle to the
screen without degrading the threedimensional effect.
In the 3-D video viewfinder

applica¬

for

a

number of theatrical

system
applica¬

tions, and the response has always
been total enthusiasm.

Among those
already had recent experi¬
with shooting 3-D, the unan¬

who have
ence

imous reaction has been

you when we were

were

"Where

shooting and

desperately need such

an aid?"
experimental unit down
to Mexico City for the last week of
shooting on AMITYVILLE HORROR
III. The response by the crew was en¬
thusiastic, and again they bemoaned
the fact that they did not have this
valuable tool from the inception of
principal photography.
We have additionally contracted
with Panavision to provide them with
five systems to go along with their im¬
proved Optimax system.
Over the years, interest in 3-D pro¬
duction would rise periodically only to
wane after a brief flurry of
activity. It
has long been felt that the promise of
We sent

3-D has

an

never

been fulfilled

due to technical
in

primarily
shortcomings, both

photography and projection. In

view of the current renewed interest

in 3-D
new

production,

we

3-D electronic

believe that

viewfinding

our

sys¬

tem is an important contribution to¬
wards the solution of some of these

technical difficulties.
46

AMERICAN

■

CINEMATOGRAPHER, JULY, 1983
American Cinematographer - July 1983

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