FRONT SCREEN PROJECTION AS A _

FILM encoucnon TECHNIQUE.

Thesis for the Degree of Me A.
MICHIGAN STATE UNNERSW  
DAWD L. KELLEY

1971

LIBRARY

THESIS

' lMichigim Stain
Um 'ctsity

 

ABSTRACT

FRONT SCREEN PROJECTION AS A
FILM PRODUCTION TECHNIQUE

BY

David L. Kelley

This thesis is a description and discussion of
front screen projection used primarily as a film produc—
tion technique. It is accompanied by a film entitled
"MASKS," which demonstrates the use of front screen
projection. The film also demonstrates some of the
problems encountered in its use.

A definition of front screen projection is given
(a method of achieving a high quality composite picture
in which the background is projected from in front of the
screen rather than from behind it), followed by a des—
cription of the primary elements that make up a front
screen system, i.e., the screen, the beam splitter, and
the beam splitter mount--camera/projection stand.

The author's experience with front screen projec-
tion is discussed in terms of a front screen system he
helped set up for the Washington County Board of Education
in Hagerstown, Maryland. Talked about are the reasons for

setting up the system, along with the technical problems

David L. Kelley

encountered in doing so. An important element here is

the discussion of the beam splitter mount that was designed
and built by the author and his co—workers especially for
this system.

Set up and operational procedures for a front
screen system are discussed, including setting up and
checking for proper alignment between the camera and pro-
jector, obtaining a prOper exposure, lighting, talent,
and camera movements.

In the Appendix is included a list of advantages
and disadvantages of front screen projection as compared
with rear screen projection, a short history of front
screen projection, the major patents covering most of the
front screen systems in use today, a set of drawings
showing the beam splitter mount built in Hagerstown, some
comments concerning the accompanying film, and a short
list of companies that either sell, rent, or use front
screen projection in actual production.

It is the author's opinion that front screen
projection is indeed a valuable tool in film (and tele-
vision) production. It does many of the things normally
done before with rear screen projection, and does them
as well, if not better, with a significant saving in

costs.

FRONT SCREEN PROJECTION AS A

FILM PRODUCTION TECHNIQUE

BY

David L. Kelley

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF ARTS

Department of Television and Radio
College of Communication Arts

1971

Accepted by the faculty of the Department of
Television and Radio, College of Communication Arts,
Michigan State University, in partial fulfillment of

the requirements for the Master of Arts degree.

 

 

Director of Thesis

ii

 

An integral part of this thesis is the film
entitled "MASKS," which is on file with the Department

of Television and Radio, Michigan State University.

iii

ACKNOWLEDGMENTS

The author would like to thank the many people who
furnished him with encouragement, assistance, and infor-
mation in the writing of this thesis, and in the produc-
tion of the film accompanying it. This includes Sharon
Cooper, Blair MacKenzie, Norm Grahl, and Jim Eckles,
all of whom were part of the Title III Project at the
Washington County Board of Education. The author is
particularly indebted to John Glosser, also part of the
Title III group, for his continued encouragement, his
assistance in the production of the film, and for his
contribution of the illustrations used in the text of
the thesis.

Thanks also to Mr. Bob Swanson of the Telesync
Corporation, and Mrs. Cheryl Dailey, Remote Sensing
Systems, Minnesota Mining and Manufacturing Company,
for technical information furnished.

Lastly, a very special thanks to the author's
wife, Terry, for her patience, encouragement, and typing

efforts.

iv

 

TABLE OF CONTENTS

Page
ACKNOWLEDGMENTS . . . . . . . . . . . . . . iv
LIST OF TABLES . . . . . . . . . . . . .
LIST OF FIGURES . . . . . . . . . . . . .
INTRODUCTION . . . . . . . . . . . . . . . 1
Chapter
I. FRONT SCREEN PROJECTION--DEFINITION AND
SHORT DISCUSSION . . . . . . . . . . 3
II. HAGERSTOWN FRONT SCREEN SYSTEM . . . . . . 15
III. OPERATIONAL PROCEDURES . . . . . . . . . 22
APPENDIX
I. Advantages and Disadvantages of Front
Screen Projection as Compared with
Rear Screen Projection . . . . . . 34
II. History . . . . . . . . . . . . 38
III. Important Patents . . . . . . . . . 44
IV. Drawings of Projection Stand Built
in Hagerstown . . . . . . . . . 59
V. The Accompanying Film . . . . . . . 65
VI. Sales, Rental, and Production Companies . 68
BIBLIOGRAPHY . . . . . . . . . . . . . . . 7O

LIST OF TABLES

Table Page

1. Optical Properties of "SCOTCHLITE"
Reflective Sheeting #7610 . . . . . . . 6

Vi

LIST OF FIGURES

Figure Page
1. Beam Splitter Mount--Camera/Projector
Stand . . . . . . . . . . . . . . 9
2. Top View of Beam Splitter Mount . . . . . . 6O
3. Front View of Beam Splitter Mount . . . . . 6l
4. Left Hand View of Beam Splitter Mount . . . . 62
5. Right Hand View of Beam Splitter Mount . . . . 63
6. Right Hand View of Beam Splitter Mount
Showing Dimensions . . . . . . . . . . 64

vii

INTRODUCTION

This paper is a discussion of a relatively new
film production technique called Front Screen Projection.

The information contained herein is, to a large
degree, based on personal experience. It includes a
definition and description of front screen projection,
set—up and operational procedures, a discussion of the
author's exposure to front screen projection, some of the
advantages and disadvantages of front screen projection
as compared with rear screen projection, and a short
history of front screen projection.

The paper is supplemented by a fifteen minute
film entitled "MASKS." It is an instructional film used
by the Washington County Board of Education, Hagerstown,
Maryland, as part of their junior high and high school
art curriculum.

I feel that the information contained in this
paper will be of particular interest to the small film
producer working with a limited budget, or in limited
studio space. It provides him with information about a

relatively simple and inexpensive technique for obtaining

realistic settings and backgrounds, and/or special effects,
through the use of composite photography. Front screen
projection is much easier to use, much cheaper to use, and
much less cumbersome than rear screen projection, and will
give consistently good results with fewer potential prob-

lems than with rear screen projection.

CHAPTER I

FRONT SCREEN PROJECTION--DEFINITION

AND SHORT DISCUSSION

Front screen projection is somewhat of a slang
term used in the film industry to describe a method of
achieving a high quality composite picture in which the
background is projected from in front of the screen
rather than from behind it.

A more technically accurate term would be "reflex

1 This becomes rather

projection composite photography."
unwieldy however, and I feel that the name front screen
projection adequately describes the end result.
There are three basic elements that make up a
front screen projection system:
1. A retro-reflective projection screen,
in front of which actors perform, and
which reflects a very high percentage

of the projected image directly back
towards the apparent light source.

 

lPhilip V. Palmquist, "Retro-Reflective Screen for
Reflex Projection Composite Photography," American
Cinematographer (July, 1969), pp. 688-690.

 

2. A beam splitter, which is in essence a
two-way front surface mirror. It is
placed at a 450 angle in front of the
camera and projector with the reflecting
side facing the projector. Its basic
purpose is to allow the projected image
to be positioned along the optical axis
of the camera lens. This is essential
to the operation of a front screen system.
3. A sturdy support system for the camera,
projector, and beam splitter. This system
must allow precise adjustments of the
camera and projector in all directions in
order to maintain their positions along
the same optical axis. Ideally, it should
allow adjustment of the beam splitter also.

What are the requirements of a front screen projec-
tion screen? They are not many, but they are demanding.
It must be a highly efficient screen, reflecting as
bright an image as possible. It must be uniformly bright
with no hot spots, reflecting light striking it from
oblique angles as efficiently as it does light striking
it at right angles. It must absorb as much ambient light
as possible, from set lights etc., in order to minimize
possible image wash out.

The standard projection screen, designed to
reflect an image bright enough to be seen in a darkened
theater by an audience viewing it from many different
angles, cannot meet these requirements.

In the late 1940's, Minnesota Mining and Manu-
facturing (3M) introduced a new material called "Scotch—

lite." More recently they have developed "SCOTCHLITE"

Brand High Gain Reflective Sheeting #7610, which is an

improvement over the old "Scotchlite." 3M describes the
product as follows:
"SCOTCHLITE" Brand High Gain Reflective Sheeting
#7610 is a plastic sheeting containing extremely
small spherical glass lenses which are uniformly
bonded at their equators. The optical glass lenses
function as microscopic spherical mirrors which
focus and return (retro-reflect) incoming light
rays directly back to the light source. The reflec-
tive surface appears neutral gray under ambient
light. The sheeting has a pressure sensitive
adhesive on the reverse side which is covered with
a removable paper liner.

Table 1 demonstrates the optical properties of
"SCOTCHLITE" Reflecting Sheeting #7610.

What all of this means, in terms of the require—
ments for a front screen projection screen, is that the
screen material now available is extremely efficient. The
gain over a perfectly diffuse white surface is approxi-
mately 1600. It means that the loss in gain at very
oblique angles is negligible. It means that the image is
only minimally affected by ambient set light. It means
that there is now available a good front screen projec-
tion screen material. "SCOTCHLITE" Reflective Sheeting
#7610 is the most widely used. There are other types,
such as the Alekan-Gerard type, but their characteristics
are essentially the same as #7610, so they need not be
discussed separately.

The retro-reflective characteristics of these new

screen materials accomplish three important things:

 

2Minnesota Mining and Manufacturing Company
Product Bulletin, Remote Sensing Systems, "SCOTCHLITE"
Brand High Gain Reflective Sheeting $7610 (March, 1971).

 

TABLE l.--Optica1 Properties of "SCOTCHLITE" Reflective
Sheeting #7610.a

 

TABLE 1 - LUMINANCE FACTOR VS. INCIDENCE ANGLE

 

Angle of Incidence 0° 10° 20° 30° 450

Luminance Factor 590 595 620 660 710

 

TABLE II - LUMINANCE FACTOR VS. DIVERGENCE ANGLE

 

 

Angle of

Divergence 0° l/4° l/3° 1/2O 3/4° 1° 1-1/2°
Luminance Factor 1610 1280 1090 590 195 115 55
Notes:

All readings in Table I were taken at an 0.5°
divergence angle. A11 readings in Table II were taken at
a 0° incidence angle.

The incidence angle is the angle formed by a light
beam striking a surface at a point, and a line perpendicu—
lar to the surface at the same point.

The divergence angle is the angle between the line
formed by a light beam striking a surface, and the line
formed by its reflected beam.

"SCOTCHLITE" Brand High Gain Reflective Sheeting
#7610 has the retro-reflectance values listed in the
above tables. The values are expressed as a multiple of
the brightness of a perfect [sic.] diffuse white surface.
This multiple is shown as the luminance factor. These
values were obtained from retro-reflective measurements
of a typical sample of #7610 Sheeting.

 

aMinnesota Mining and Manufacturing Company Product
Bulletin, Remote Sensing Systems, "SCOTCHLITE" Brand High
Gain Reflective Sheeting #7610 YMarch, 1971).

 

 

l. The gain is so high that those portions of
the projected image that fall on foreground
objects are not seen by the film.

2. The reflected image is bright enough to
allow the camera to film at a relatively
small aperture. This increases the depth
of field, giving the actors much greater
freedom.

3. Because the image is virtually unaffected by
ambient set light, the problem of image
washout is much less severe.

At this point it should be explained further just
why that part of the image that is projected onto talent
and other foreground objects is not seen. There are two
elements involved here, both of which are the result of
the characteristics of the retro-reflective screen.

First, the difference between the brightness of
the image reflected from the retro—reflective screen and
that reflected from the talent and most other foreground
objects is greater than the latitude of the film, and
hence generally beyond the capability of the film to
record it.

If there are no set lights on, the talent and
foreground set will be sillhouetted against the projected
background. Under this condition it is possible that
certain portions of the projected image would be visible
on the talent and other parts of the set. They would
probably appear as mottled splotches of light. This brings
us to the second element, that being set lighting. Once

the set is prOperly lit and balanced against the projected

background, the combined effect of the above-mentioned

difference in image brightness, and the bright set lights
washing out what little image is reflected, will result
in the fact that those portions of the projected image
falling on talent and other foreground objects are
invisible.

The second basic element in a front screen projec—
tion system is the beam splitter. As I said above, it is
basically a two-way front surface mirror. It is placed
in front of the camera and projector at a 450 angle with
the reflecting side towards the projector (see Figure l).
The projected image is reflected off the beam splitter
onto the screen, and the camera shoots through the beam
splitter to film that image. Its function is to allow
the projected image to be positioned along the same
optical axis as the camera lens. Put another way, it
allows the camera and the projector to operate along the
same optical axis so that the camera becomes the apparent
light source. The precise alignment of the camera and
projector along this common optical axis is extremely
critical and important, for this is the basic principle
upon which front screen projection operates. The beam
splitter, by allowing the camera and projector to operate
on a common optical axis, accomplishes two things. First
of all it is the function of the retro—reflective screen
to focus and reflect most of the light striking it, i.e.,
the image, directly back to the light source. The camera

then, being the apparent light source, is able to film

 

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10

the brightest possible image. Secondly, proper alignment
along this common axis insures that the shadow cast by
foreground objects (talent etc.) is cast directly behind
them, with no matt fringing of the shadow being visible.
The visibility of a matt shadow immediately indicates that
the system is out of alignment. It significantly lowers
the quality of the composite picture, in most cases making
it unacceptable.

A matt shadow is quite visible in one of the
scenes in the film "MASKS" which accompanies this thesis.
It occurs when the camera moves diagonally down and to
the right and zooms all the way in to show a close-up of
one of the masks sitting on a pillar. The narrator
describes the mask as a skull that had been covered with
plaster and then decorated. Another shadow occurs a
little later when talking about a New Guinea mask. Again,
the camera is in tight for a close-up. In both cases the
shadow was the result of the camera movement throwing the
system out of alignment. It was deemed acceptable because
of other production problems, and because it was so far
out of focus. But it seriously lowered the quality of
the composite picture, and significantly compromised the
quality of the final film.

There are various kinds of beam splitters ranging

from a thin sheet of flashed plastic called a pellicle to

11

to the standard two—way front surface mirror.3 Theore-
tically almost anything that can reflect and transmit
light at the same time can be used as a beam splitter so
long as the reflectance-transmission ratio is within
workable limits, so long as it is absolutely flat so
that it doesn't distort the reflected image, and so long
as it generally reflects a high quality image.

The reflectance-transmission ratio is an important
factor. There is no specific ratio for all cases, but
generally speaking it should probably be somewhere around
50 per cent reflectance, 50 per cent transmission. It
should be tailored to the needs of the individual system
however. Of course the more it reflects the less it will
transmit, which means a larger exposure compensation
either in the aperture setting or in the lighting. The
reverse of this is also true. The more it transmits the
less it will reflect.

This may create a need for a higher wattage pro—
jection bulb, which in turn leads to a possible noise
problem due to the larger cooling fans required on the
projector.

To a large extent the quality of the projected
image is determined by the beam splitter. It is recom-
mended that as high a quality beam splitter as possible

be used, for the front screen projection system is

 

3Raymond Fielding, The Technique of Special
Effects Cinematography (New York: Communication Arts
Books, Hastings House, 1965), p. 313.

 

 

 

12

highly analogous to the proverbial chain and its weakest
link.

The third basic element in a front screen system
is the beam splitter mount, which, in most cases, is also
the camera/projector stand (see Figure 1). This is an
important element because of the highly critical nature
of the alignment between the camera, the projector, and
the beam splitter.

What are the requirements for such a stand? First
of all it should be sturdy. Any movement or vibration
of the camera and/or the projector and/or the beam
splitter is unacceptable. If the system should move,
or vibrate, out of alignment it will cause a visible matt
shadow. This could create the rather novel effect of
the background moving, which can be shocking in some cases.
Secondly it must allow for the easy adjustment in all
directions of the camera and projector. Ideally it will
also allow for the adjustment in all directions of the
beam splitter, but this type of mount can get to be a bit
complicated.

Generally speaking it is probably better to have
the beam splitter mount and the camera/projector stand
combined into one unit. This allows for more precise
adjustments, and fewer potential alignment problems.

An additional element that needs some considera-
tion at this point is the type of equipment to be used in

terms of cameras and projectors. Almost any kind of

13

camera can be used, so long as it will take a picture,
and so long as it will fit on the stand so that it comes
into proper alignment. Naturally the better the camera
and lens, the better the end product, but this choice is
best left up to the individual producer.

To a large extent the same holds true for the
projectors. First of all we will assume that 2x2 slides
are to be used for the background, rather than motion
pictures. Provided it will fit on the stand properly
almost any projector will work. The amount of gadgetry
on the projector to help accomplish dissolves, supers,
etc. is up to the individual producer. Again, the better
the quality of the projector and the projection lens the
better the end product.

A point to keep in mind is that the smaller the
wattage requirements for the projection lamp are, the
smaller the cooling requirements for the projectors are,
which might possibly solve a serious sound problem.
Unlike rear projection, the projector in front screen
projection operates from the same place the camera does,
which is generally quite close to the talent. If large
cooling fans are required, and the projectors are not
mounted in sound conditioned boxes, these fans will be
picked up on mike. This, obviously, is undesirable.

I mentioned above that we would make the assump-
tion that 2x2 slides would be used for the backgrounds

rather than motion pictures. Motion picture backgrounds

14

are entirely possible, and have been used in many films.
But it is rather more complicated, and quite a bit more
costly than the design of the system under discussion
allows for. To be done properly the camera and projector
must be interlocked on a frame for frame basis. This
requires the use of a sylsen interlock system which is
quite expensive, as is adapting a camera to such an
interlock system. Motion picture projectors are also
rather noisy creatures, and this noise factor must be

taken into account.

CHAPTER II

HAGERSTOWN FRONT SCREEN SYSTEM

For the two years prior to June, 1970, I was
involved in an experimental film project with the Washing-
ton County Board of Education, Hagerstown, Maryland.
The project was funded under a Title III grant from the
Department of Health, Education, and Welfare. Its basic
goal was to experiment, on film, with different types of
television teaching techniques in an attempt to improve
television instruction. The target audience for the final
two years of the project, which ended in June of 1970, was
the seventh, eighth, and eleventh grades of the Washington
County public school system.

The project produced a film series called ART::

A REFLECTION OF MAN. It dealt primarily with art in the

 

humanities, covering such areas as the origins of art,
art history and philosophy, the effect of art on society,
and the effect of society on art. A few basic "how to"

type programs were also produced.

15

16

The series was produced and used as supplemental
instruction in the county's basic art curriculum. How—
ever, because of the very broad approach to the subject
matter, the series also served in a cross-curriculum
capacity as supplemental instruction in English and social
studies.

One of the major problems, as is the case with
most visual presentations, was how to present the visual
information in an interesting and informative way. This
was a rather all-inclusive problem, ranging from the
presentation of art examples to sets within which to
place talent.

For the most part the problem was handled in the
traditional manner, i.e., the use of cut-aways, copying
slides and pictures onto film, location shooting, and use
of models and miniatures, etc.

Approximately eight months before the end of the
project we became aware of front screen projection and
its potential application to our particular problems. We
were able to get enough money approved to purchase a
large screen and two beam splitters. The catch was that
the project would have to design and build its own beam
splitter mount.

The project already had the necessary camera gear
and projection equipment. The camera was an Auricon

Pro-600, with an Angenieux 12-120 zoom lens. This was

17

mounted on an NCE fluid tripid head, which would in turn
be mounted on the beam splitter mount by means of a standard
high hat. The projectors were made by Spindler and
Sauppee. They were controlled by a special control unit
that allowed supering, timed dissolves, etc. Each pro—
jector had a two and a three inch lens.
The screen was 10' x 14', and covered one whole
wall of the studio. It was bound and grommeted on all
four sides, and was hung from a special framework that
had been attached to both side walls, the ceiling, and
the floor of the studio. This allowed for the screen to
be laced on all four sides, providing tension in all direc—
tions. With the proper tension, and a couple of days hanging
time, all the wrinkles pulled out and it hung perfectly flat.
The beam splitter mount was the difficult part,
because all we really had to go on for the design were
some basic drawings in an article in American Cinemato-
grapher.1 Figure 1 shows the basic mount with the
equipment in position. In Appendix IV I have included a
complete set of drawings. These drawings show the mount
from various angles, with the camera and projectors in
position. One of the illustrations gives some rough
dimensions. Not all dimensions are given however, for it

is not the purpose of these drawings to act as blue

 

1"A Double Front Projection Set-up that Uses
Slides for Backgrounds," American Cinematographer (April,
1970). PP. 340, 369.

 

18

prints. There are a couple of problems with the mount
that I will get to shortly. The drawings are included
simply to show what kind of a mount we built in Hagerstown,
and to perhaps give some direction to other producers

who may want to design and build their own mount.

When first put into operation the mount was
placed on a sturdy projection table. Since I left Hagers—
town they have moved it to an even sturdier table, but one
that they can move in and out of the studio more easily.
Obviously the best support would be one that is especially
built for it. Hagerstown tells me that this is in the
works, but there are other more pressing items, so it will
be some time before it is a reality. In the meantime the
table top will suffice. This points up the fact that
nearly any table can act as a base for the stand, so long
as it gets the camera and projector to the necessary
height, and so long as it is good and sturdy and doesn't
wobble around.

Because of the fact that the camera and the projec—
tor are both positioned on the mount, and because the
optical alignment between them is critical, sturdiness was
an important consideration in construction. We used 3/4"
plywood, with all joints first being glued together and
then screwed down tight. When it was finished, the whole
mount was painted a flat black. The reason for this was
to eliminate any secondary reflections that might cause
ghost images. This was particularly important in the

light traps, indicated by the shaded areas in Figure l.

19

When the mount was finished, the whole system was
set up and tests were run. It was at this point that we
discovered two bad design faults. As I mentioned above,
the screen was 10' x 14', and we knew that in some produc—
tions we would want to fill that screen with an image. A
maximum projection throw of about 20' meant that we would
have to use wide angle projection lenses. A 2 inch lens
filled the screen nicely, except when on the mount. Here
we soon discovered that the opening in the front of the
mount through wich the image was reflected, and through
which the camera filmed that image (see Figure l), was not
wide enough. It cropped a significant portion of the
projected picture area. This resulted in having to use
3 inch lenses and living with a smaller image size, the
compromise here being that we could live more easily with
a smaller image size than we could with an actual loss of
picture information.

The second problem was that the design allowed for
almost no along-axis adjustment of the camera position.

It is important that the front nodal points of both the
camera and projection lenses be equidistant from the
number 1 beam splitter (see Figure 1). If this distance
is not equal a matt shadow appears. There was some degree
of along-axis adjustment and we were able to minimize the
shadow, but as the talent moved further away from center
screen the shadow became increasingly apparent, resulting

in an unacceptable picture.

20

The proper solution to both of these problems was
to redesign and rebuild the mount. If we wanted the system
in Operation before the end of the project, however, this
was an impossibility. So, for the time being, we had to
accept a smaller image size and very limited talent
movement.

The people in Hagerstown tell me that they are
still working with these same limitations, but that they
are designing a new mount. Their indications are that the
new mount will have an extension where the camera is
mounted that will allow axial movement of the camera along
the common optical axis. The beam splitters will be
mounted closer to each other, and the projectors will be
mounted closer to the beam splitters. They feel that this
will create only a slightly smaller image, but one that
will project through the front of the mount without being
cropped when using 2 inch projection lenses (see Figure l
as a reference for understanding these changes).

A problem that became immediately and painfully
apparent was the very limited camera movement when there
was talent in the shot. This is due to the fact that the
alignment between the camera and projector is extremely
critical. They must operate along the same optical axis or
a matt shadow is created. When panning or tilting on a
standard tripod head it is impossible to maintain this
alignment because the lens is way out in front of the

center of rotation; which means that it must swing through

21

an arc in order to accomplish the move. We found that

with no talent or foreground object in the shot we could

pan and tilt to a rather large degree with only a minor

loss in image brightness. This is because the arc through
which the lens moved stayed within an acceptable angle of
reflectance from the retro-reflective screen without an
objectionable loss of image brightness. This is demonstrated
early in the accompanying film in those shots where the
camera moves in on the large world map used as a background.

Panning and tilting are indeed possible with fore—
ground objects in the shot, but they require a special
nodal point pan head that moves the lens back to the center
of rotation of the head. This means that the camera body
swings through the arc rather than the lens, thus main—
taining proper alignment. These heads are specially
designed and built, and are rather expensive, so that they
were unavailable to us in Hagerstown.

The system, with these limitations, functions quite
well, however. The film accompanying this written portion
of the thesis will demonstrate this. It allowed us to
present the visual information in a much more interesting,
informative, and creative manner. They are now using it
in Hagerstown as an integral part of their instructional
television system, using it both in television and film

production to enhance their daily lessons.

CHAPTER III

OPERATIONAL PROCEDURES

This section will deal with the set up and opera— “
tion of a front screen system. It assumes that the scree
is already up. There is one further thing I might say
about the screen, however, and that is that it is important
that it be perpendicular to the axis of projection.
Although, to a large extent this is a function of projec-
tor placement, it is important that the screen be hung
properly. It must be hung in such a way as to be perpen—
dicular to the axis of projection, and with enough tension
all the way around so that the wrinkles pull out and the
screen hangs flat.

The first thing to check when setting up a front
screen system is whether or not the projection axis is
perpendicular to the projection plane. It is difficult
to say just how to do this as it will depend on the shape
and design of the individual beam splitter mount—projec-
tion stand. Generally speaking however, it can be
accomplished by running a tape measure from the corners

of the leading edge of the mount to the corners of the

22

23

screen, and adjusting the mount until the proper measure—
ments are obtained.

Perhaps the most important and critical adjustment
to be made is that of bringing the camera and projector
into proper alignment. Fortunately it is a relatively
simple thing to accomplish.

One method is to place the reflected image of the
projection lamp filaments in the center of the camera
lens.1 By standing in front of the mount and looking
through the number one beam splitter, one looks directly
into the camera lens (see Figure 1). One also sees the
reflected image of the projection lamp filaments. Proper
coaxial alignment then becomes a matter of panning and
tilting the projector until the reflected image of the
lamp filaments falls exactly in the center of the camera
lens. It is suggested that a neutral density filter be
placed over the projection lens to bring the light
intensity down to an acceptable level for this operation.
In some cases, if one is using a projector control unit
such as we had in Hagerstown, he can accomplish the same
thing as with the neutral density filter by putting the
control unit in the ready or hold position. With some
units this setting allows just enough voltage to pass

through the lamp to cause the filaments to glow slightly,

 

1Instructions for the operation of a Retro-
Reflective Front Screen Projection System, prepared by
the Telesync Corporation, 20 Insley Street, Demarest,
New Jersey, 07627. (Mimeographed.)

24

but with enough intensity for their reflected image to be
clearly seen in the beam splitter.

The problem with this method is that it doesn't
indicate proper along-axis alignment. Mr. L. F. Rider,
in an article in American Cinematographer entitled The

Alekan-Gerard Process of Composite Photography,2 explains

 

a method to determine both the proper along-axis and the
proper coaxial alignment.

A piece of beaded screen material about nine inches
square should be mounted on a thin stiff board of
the same size which, in turn, is fixed to the end
of a rod of convenient length. This device is used
as a probe, to be inserted into the camera field
approximately where the foreground subject is to be
located. If the optical alignment is correct, then
the probe target, as seen through the camera, will
merge almost indistinguishably into the background
and will be free from shadow fringing. Sould an
all-round shadow fringe be seen, then either the
camera is too far back along the common axis, or
the projector is too near the mirror. Should the
camera be tOO far forward, then a fringe will be
seen on that edge of the target which is nearest
the optical axis, but this effect is only observed
when the target is wholly off-axis.

I did not become aware of this technique until
after I had left Hagerstown. It would have been a great
help to us in setting up that system.

The proper alignment between the camera and the
projector is extremely critical. If these two elements

are not in proper alignment the system will not function

 

2 .
L. F. Rider, "The Alekan-Gerard Process of Com—

posit PhotOgraphyf American Cinematographer (July, 1962).
p. 430.

25

properly, and there will be a matt shadow that cannot be
eliminated.

Obtaining the correct exposure for the background
is rather important, for it is this exposure that will
determine the exposure for the talent and other foreground
objects.

This reading must be taken from the position of the
camera lens. There are a number of reasons for this, the
first of which has to do with the basic principle upon
which front screen projection is based. As I mentioned
earlier, this principle requires that the camera and pro-
jector operate on a common optical axis, and that it is
function of the beam splitter to allow this. It does so
by reflecting the projected image onto the screen and,
being a two-way front surface mirror, allowing the camera
to shoot through it to film that image. If one stands in
front of the beam splitter then, he blocks out the pro-
jected image.

Secondly, the highly directional characteristics
of the retro-reflective screen require that the reading
be taken from the camera lens position (see Table 1 under
the discussion of screen material in Chapter I). The
.second table shows us that as the angle of divergence
jJncreases, the luminance factor falls off quite rapidly.
£3ince the basic principal upon which front screen projec—
t:ion.is based requires that the camera and projector

cherate along a common optical axis, and since it is the

 

26

purpose of the retro—reflective screen to focus and
reflect most of the light striking it directly back to the
light source, and since the camera becomes the apparent
light souce, the brightest image is seen from the camera
position. A light meter held at the position of the
camera lens then, will see and read exactly what the
camera will film. But as the light meter moves away from
this position, and hence away from the common optical
axis, the brightness of the image it is reading falls off
quite rapidly, as Table II shows, and an incorrect reading
will be obtained.

Also, again because of the highly directional
characteristics of the screen, it is almost impossible to
see the projected image from anywhere except the camera
position.

Because the most accurate reading is taken from
the camera position, a reflected reading must be used
rather than an incident reading. We found in Hagerstown
that a meter with a normal angle of acceptance, one that
read the whole image and automotically averaged the
exposure, was more convenient. This will depend on the
individual system however. In some cases it might be
easier to use a spot meter to read many small areas of
the image, and then average the exposure manually after
all readings are taken.

Another method to be considered is to use a 35mm

single lens reflex still camera with interchangeable

 

27

lenses, and a through-the-lens metering system. The

camera could be set up in place of the motion picture camera,
with the nodal point of the lens in the proper place. The
operator could then see exactly what his meter is reading,
and could change lenses to make it read exactly what he
wants it to.

One important point to keep in mind is the neces—
sity for maintaining a consistant exposure in all back-
ground slide. If the density of these slides varies
more than about 15 per cent, the brightness of the pro-
jected background will vary from slide to slide and the
quality of the final composite picture will be greatly
decreased, or even be unacceptable.

Once the basic exposure for the background slides
is determined, one can begin to light the set. This can
be done with an incident meter, remembering always to allow
for the light loss through the beam splitter. As I men-
tioned earlier, the beam splitter is basically a two-way
front surface mirror that reflects part of the light
striking it and transmits the rest of it. This is usually
expressed in terms of a percentage. The beam splitters
used in Hagerstown reflected 30 per cent of the light and
transmitted 70 per cent. This means simply that unless
the light loss was taken into consideration when taking
the reading, the picture will be 30 per cent underexposed.
It has the same effect as putting a neutral density filter

on the camera lens, and then not allowing for the filter

28

factor when taking the picture. It is a good idea to run
some tests when setting up the system to determine the
exact amount of this loss. This can be accounted for,
then, when taking the reading by either adjusting the
aperture, or adjusting the ASA rating of the film.

A color correction filter on the camera may be
necessary to compensate for a possible color shift caused
by the reflective coating on the beam splitter. All coat—
ings vary slightly, but a 10, 20, or 30cc magenta filter
should take care of most situations.3 Again, some tests
should be run. If the shift is slight, it can be cor-
rected at the lab during printing, doing away with the
need for a filter.

Lighting set ups can be pretty much standard, but
even with the retro-reflective screen materials it is a
good idea to keep the ambient set light falling on the
screen as low as possible. But this is not the absolute
requirement that it is in rear screen projection. Lights
should be high and at a side angle of about 400. This
allows ambient light rays from the set lights to strike
the screen from an oblique angle, and for shadows created

by these lights to fall on the floor rather than the screen.

 

3Letter from Mr. Bob Swanson, Telesync Corporation,
20 Insley St., Demarest, New Jersey, 07627, to Mr. Blair L.
MacKenzie, Title III ETV Project, Washington County Board
of Education, Hagerstown, Maryland, 21740, December 26,
1969.

29

To get the proper balance between the projected
background and the foreground subjects will take some
practice. Because the new retro—reflective screens have
such a high gain, the reflected image can easily overpower
the scene, and the talent becomes lost in the background.
This should generally be avoided as it looks unreal. It
looks as though someone is standing in front of a pro-
jected image, and this is neither the purpose of front
screen projection, nor does it demonstrate the quality
that it is capable of.

In the accompanying film there are a number of
scenes in which this occurs. It is perhaps best demon-
strated in the scene in which the background slide is a
stage coach robbery. Talent is both poorly lit and poorly
balanced against the background, and as a consequence,
tends to become lost in it.

In my judgment it is better to keep the background
light level down anywhere between 1/4 and one full stop
below what the foreground subjects are lit for, dependent
upon the requirements of the individual production. It
may be necessary to put a neutral density filter on the
projection lens to bring the background intensity down to
an acceptable level.

Talent should be placed approximately six to
eight feet in front of the screen. This gives separation
between talent and background, generally allows any

shadows created by set lights to fall on the floor rather

30

than the screen, and keeps any intensely concentrated rays
of light from striking the screen. In spite of the highly
directional characteristics of the retro-reflective
screen material, some part of the light rays are reflected
in all directions and are bound to find their way into the
camera lens. This is more likely to be a problem with a
highly concentrated ray of light directly striking the
screen than with ambient set light.

Talent may have some trouble working in front of
a front screen system for the first time due to the fact
that the camera lens becomes a rather bright spot of light.
This is because of the projection lamp filaments being
supered over the center of the camera lens, and although
there is generally a slide up they still create a very
bright spot of light. The other problem is that the
talent can not see the image on the screen. As I men-
tioned earlier, about the only place the image can be seen
is from the camera position. This problem is significant
only when the talent must make reference to certain ele-
ments within the image. In most cases a solution can be
found during rehearsal. In any event they are not serious
drawbacks, and most talent will adjust quite readily.

Camera movements, at least in terms of trucking
and dolly shots, are obviously out. To accomplish this
type of movement would require moving the camera, which
in turn means moving the projector, which just wouldn't

work.

31

Pans and tilts are possible, but only by using a
special pan head that is designed for front nodal point
panning and tilting. A head of this nature, because the
point of rotation is at the front nodal point of the lens
rather than at the camera body, does not throw the lens
out of alignment when a move is made. Even without this
special nodal point pan head some movements can be made,
but they are extremely limited. If there is no talent in
the shot somewhat more freedom is allowed as there is no
shadow problem to content with; only a loss in light level,
and here there is a bit more latitude. This is demonstrated
in the accompanying film when the camera pans and zooms in
on the large map used as a background.

Zooms are also possible, but they introduce some
special problems all their own. The major problem is in
maintaining prOper perspective. In theory, the same focal
length lenses should be used in the camera and projector
as were used on location to shoot the background slides.
This is not an absolute rule however, and can be hedged
quite a bit if one is very careful. The major problem with
perspective begins when one is using a three-dimensional or
real scene for a background and tries to make a long zoom.
The established perspective is destroyed, and the scene
begins to look unreal. In Hagerstown we found that short
zooms were generally acceptable, but that one had to be
extremely careful. In general a cut is better for long

movements, in which a new slide can be put up with the

32

proper perspective to match the new camera position and
field of View.

The other major problem is that of throwing the
system out of alignment and creating a matt shadow. As
long as one zooms straight in or out there is very little
problem. But if one is using talent and wants to zoom, it
is very difficult, if not impossible, to make a straight
in or out movement and maintain a prOperly composed picture.
It is generally necessary to pan and/or tilt to maintain
proper composition. In Hagerstown this was quite diffi-
cult, but, as I said above, limited moves were possible if
one was very careful. Obviously, a nodal point pan head

would have solved the problem.

APPENDICES

33

APPENDIX I

ADVANTAGES AND DISADVANTAGES OF FRONT
SCREEN PROJECTION AS COMPARED WITH

REAR SCREEN PROJECTION

34

ADVANTAGES AND DISADVANTAGES OF FRONT SCREEN

PROJECTION AS COMPARED WITH REAR SCREEN PROJECTION

Some of the advantages of front screen projection

are as follows:

1.

Due to the technical requirements of rear screen
projection, it needs as much studio space behind
thescreen as it does in front of it. Front
screen projection can cut this space requirement
in half.

Good rear screen projection requires a powerful
light source, and it generally uses 4x5 glass
mounted transparencies. This means heavy, bulky,
noisy projection equipment. Front screen projec-
tion can get satisfactory results with a 35mm
slide, and a standard slide projector with only

a 500 watt lamp. The projection equipment
required is small and light, and the noise problems
are greatly reduced.

Rear screen projection has a problem with a hot
spot in the projected image. This problem does

not exist in front screen projection.

35

36

4. The image in front screen projection is generally
as good as, if not better than, rear screen
projection. This is because it is not compromised
by diffusion and transmission through the screen.

This generally also means more highly saturated

colors.
F
5. Because of the characteristics of the front screen -
projection screen, lighting is greatly simplified ;
over the lighting set ups required in rear screen i
projection. Standard lighting set ups can be E

 

used, or the lighting director can be as creative
as he wants or needs to be without fear of bad
image wash out.

6. Front screen projection is considerably less
expensive to set up and operate than rear screen
projection. Savings are noted primarily in the
areas of basic equipment costs, and in studio
and power requirements.

7. By covering portions of the foreground set with
reflex-screen material, the actor can be made
to appear to walk behind objects which appear in
the background plate or stereo.1
Some of the disadvantages of front screen projec-

tion are as follows:

1. , Camera movements are rather limited. Trucking and

dolly shots are out. Pans and tilts are limited.

 

lRaymond Fielding, op. cit., p. 322.

37

2. Because of the proximity of the talent's micro-
phone to the projector there is a potentially
serious sound problem.

The advantages of front screen projection over
rear screen projection are obvious. In most cases it
gives quality equal to that of rear screen projection,
and is generally cheaper and easier to use than rear
screen projection. This should be of particular signi-
ficance to the small producer working with limited
budgets.

The first disadvantage can be crippling for some
kinds of shows. It can be easily dealt with however, if
the director is absolutely certain of his shot require—

ments before going into production.

 

 

APPENDIX II

HISTORY

38

HISTORY

Throughout the history of both still and motion

picture photography many attempts have been made to

 

achieve a high quality composite picture through the use ET
of a reflected image projected from in front of the

screen rather than from behind it. A couple of days of

digging around the patent files in the Detroit Public r
Library unearthed some rather interesting and potentially :fl

good ideas. For those interested in further research
along these lines, I have included in the bibliography
the numbers of some of these patents. Many of them have
no direct relevance to the development of front screen
projection to any greater extent than that they served
as sources of ideas. They served well in this capacity
however, and from this point of view it is indeed an
interesting area of research.

In Appendix III I have reproduced the three major
patents under which most front screen projection systems
in use today operate. They are 0.8. patent numbers
2,727,427, and 2,727,429, and British patent number

768,394.

39

40

As I said above, many attempts have been made to
achieve a high quality front screen projection system.
Despite these attempts, most of the efforts went into
rear screen projection, which has become an industry

standard.

The main problem facing front screen projection

seems to have been technological, with the most important FEW
element being the lack of a good high quality, high gain
retro-reflective screen material. This meant that camera- 5
men had to work with wide Open apertures giving them a i
very shallow depth of field, particularly with longer i_4

lenses. In some cases the reflected light level was so
low it could not be filmed. It also meant that talent
had very little freedom of movement towards or away from
the camera. This resulted in having to place talent very
close to the screen, causing shadows and image wash out
due to light on the screen.

There seems to have been one other element involved.
It is rather subjective, and I'm not certain just how much
it really affected the development of front screen projec-
tion. This is a seeming reluctance and slowness on the
part of the film industry to accept and utilize front
screen projection, even after the technology was avail-
able. Their attitude seems to have been that this new
technique is untried and has many problems that need to
be worked out. Our old system of rear screen projection
works, the problems have been worked out, it gives con-

sistently high quality results, so why change?

41

The needed technology became available in the late
1940's with the introduction of "Scotchlite" by the Minne-
sota Mining and Manufacturing Company. This was a new
development in projection screen material, being retro-
reflective and having a very high gain. Shortly after

the introduction of this new screen material, the Motion

FTI
Picture Research Council, in association with the Stanford :
Research Institute, began research and development of the 1
front screen projection technique.l

Beginning in 1950 the Motion Picture Research

 

Council Bulletin began publishing reports of their work
on the front screen technique.2 In December of 1955, two
patents, number 2,727,427 and number 2,727,429 were granted
to an independent inventor by the name of will F.
Jenkins.3

At about the same time a process very similar in
nature to that of Jenkins was being developed in Europe
by two Frenchmen named Alekan and Gerard. In 1957 a
British patent, number 768,394 was issued to Henry Albert
Alekan, and has since been acquired by the J. Arthur Rank

Organization.

 

lRaymond Fielding, op. cit., p. 306.

21bid.

3Ibid.

41bid.

42

It wasn't until the middle 1960's that Hollywood
finally began to take a hard look at front screen projec-
tion. It is generally felt that the film that caused them
to look was Stanley Kubricks' "2001: A Space Odyssey." In
the film Mr. Kubrick uses front screen projection through-
out the whole opening sequence to tell the story of the
evolution of man. Since "2001" other films, such as

"Tora Tora Tora,‘ have also made much use of the technique.
Television also began finding uses for it, and its i
use has increased many times in both mediums. Today there
are companies that either sell or rent complete systems.
The sales do not generally include a camera, but they do
include slide projectors, beam splitters, the beam splitter
mount, and what ever size screen is needed. Rentals on
the other hand, generally include everything, from the
camera through the screen, plus a crew to run it. There
are also a few film production companies and television
studios which have installed front screen systems and use
them for contract jobs. I have included the names of
some of these companies in Appendix VI.
Front screen projection is a good tool. Mr.
Kubrick demonstrated that it was indeed a viable and
creative technique. I doubt that it will ever totally
replace rear screen projection, nor is there a need to.

'Phey are both usable tools, but used properly front

Scmeen projection can now assume many of the jobs that

43

formerly had to be done with rear screen projection, and
do so with a significant saving in costs, and with a level

of quality that is at least equal to rear screen projec-

tion, if not better.

 

 

APPENDIX III

IMPORTANT PATENTS

44

Eat!“
3. .

 

45

PATENT SPECIFICATION
768,394

Date of Application and filing Complete Specification: jan. 3. I955.
No. 56,:55.

Application made In France on jan. 7. I954.

Complete Specification Published: Feb. l3. I957. x‘

 

Index at Acceptancez—Classes 40(3). F9124; 97(1), 0; and 98(2). D17.

 

International Chssiflcationz—Gmhd. HMn.

COMPLETE SPECIFICATION

Improvements in and relating to Apparatus for Taking Composite
Pictures by Photography or Television

1, "mm Answer ALI-IRAN, a citizen of the
French Iii-public, of 46 Inc de la Toun-lle,
Boulogncmur-Seine (Seine), l-‘rance, do here-
by declare the invention, for which I

by disposing the projector, the camera and
the objects, whether they are pemona or
material objects, on the name aide of the
screen and in utilizing a screen having a

5 pray that a patent may he granted to me, reflecting power which is considerahly greater 50
and the method hy which it is to he pcr- than that of said material ohjccta, whereby
formed, to be particularly tlt‘scl‘lll‘d in and the projection on this screen may he obtained
hy the following statement:—- with a lighting which is of such power that

'l'hi» invention rclatcs to a process and it is not reflected in the portion thereof

l0 device for taking compmite shots for the which strikes the material ohjecta and 65
cinema, photography or lt‘lt‘\'l>l0ll which sulN-qtu-ntIyamen-irsoulyonthehackground
permits {lssnt'lilllllg in the mute shot persons and not on mid objects or parents.
and Material Ulrjl'l‘lH which are illuminated To this end, it has hecn prowl-ted to
hy a natural or artilir ial light. and an image, utilise for the M'n'vxll a self-collimating aurfaaa

l5 lll'UjN‘lUlUl-UHIH'l't't'llttlllillhtllljt't‘llllttllt‘l‘ constituted hy a large numher of self- 00
executed by hand (drawings, pictures) or collimating elements of very small size
hy photography (photos on paper, trans. supported on a suitahle supptwt, and to
parent-in, cinema films). The usual prm-es-i dispose a projecting apparatus, a recording
employed in uhtaining this type of shot, camera and a reflecting device in such

20 known as “transparency” or "li.-ickgi'ouiid", manner that the virtual image formed by 65
consists in placing the purple and the said reflective device, of one of the objectives
illuminated material ohjccts in front of a. of the projecting apjmratua and recording
translucid M'rl‘t'll on which the images are. earner}? coincides with the other of these
projected by meami of a projector placed on objectives.

1'5 the other i-ide of the screen relative to the Fig. l is a diagrammatic view of auch I 70
camera. self-collimating i-urfaee or a reflex reflector

This prom.“ lma two main disadvantages. on which a homo or ray ohlichly impinging
It rupiirm, firstly, the use of a \‘cry hright. thereon products a concentrated cone of
projector in order to cnal-le a fairly large reflected light in a reflex manner returning

5'” screen to be. utilized and therchy ohtain it towards the murce ol'ray or beam. 75
aufliciently deep flcld and, secondly. the use Many types of i-elf-t-ollilnating element.
of a vast studio owing to the great. distance are lznown. The property of these element.
between the projector and the camera. is to return an incident ray as a cone of

For remedying these disadvantage» it has very small angular spread and whoae axis

3'5 already l-ccn projmsi-d to utilize lil‘twt‘sst's in coincides with the direction of the incident 80
which the l';tll|t'l‘it and the projector are ray. These wlf-collimating clement» consist
placed on the .‘JIIK' hltlt' ofa reflecting screen. for example of pyramidu having three
For example, it is known to use a screen pt't'pt'lttllt'ulitl' faces, elements each formed
consisting of a large spherical concave mirror of two spherical elements having difl'erent

1') which iaofonc plct't'urt'ulllprlscs juxtaposed radii hut suhstantially the same «intro of 85
clement-i. This process is too delicate in curvature, or i-imple hall» or spheres of 5
operation. the slightest accidental dis- refractive material (of suitahle refractive
phu-cmcnt of any element marriug the result. index) etc., coinhincd with a reflecting or
This prohli-m in solhul by the pltN'cllt Henri-reflecting Mirface.

l-i inn-mien which collslxls in taking the shot Many applic..tiom of these surface; are 90

[Price 3.. 04.]

 

It)

210

35

45

50

55

05

46

768,304

 

-——.—— -_—.—_'—-———

known, notably for rendering publicity
panels visible at night, highway signals,
vehicle signals, path beacons at. the bottom
of underground caves or pits, etc.

l‘carly screens have already been utilized
for the projections of cinema scenes. These
screens comprise a layer of fine halls of
ordinary glass, whose index of refraction
is about 1.5.

The use of such screen for taking photo-
graphic .sbots proved unsatisfactory. In
fact the balls of this kind are practically not
sclf~collimating but diffuse, that is the beam
of reflected rays forms a very diverging cone,
this being necessary to ensure that the
projection is seen by the entire audience.
The problem for a projection for a photo-
graphic .sliot is the revcr.~c, since in this case
the reflected beam must be concentrated as
far as possible towards the lens of the camera.
Thus such ordinary pearly screens cannot
be utilised in the process of the invention
for, firstly, their reflecting power is in-
suflicient and requires a too strong source of
light for projection and this would cause the
image to appear on the persons and material
objects. Secondly, the white appearance of
these pearly screens drowns the projected
image in a white haze, the screen receiving
and diffusing the ambiant light illuminating
the persons.

The invention has for its object an in-
stallation for taking combined views by
still-photography, cinematography or tele-
vision, in which persons or material objects
illuminated by a source of light and optically
projected images are photographed simul-
tnnconsly, comprising a camera and an
optical pmjector located on the same side
of a projection screen, and an optical re.
fleeting device so disposed with respect to
said camera and said projector that the
virtual image formed by said reflecting
device, of the objective of one coincides
substantially with the objective of the other,
said projection screen being formed of a
layer of spherical beads made of transparent
material, the rear portion of each head being
embedded in a reflecting layer which supports
the beads, characterized in this that the
transparent material has a refraction index
between 1.7 and 2.

A screen made of beads of material of
this kind is known and is not claimed per xc.

Plastic materials are known which satisfy
this condition and, furthermore, recent
discoveries have permitted the mannfaetmeof
glasses having an index of refracti -n as much
as 2.0."). Experiments carried out by Applicant
with screens comprising glass “3114 of this
nature and having an index of refraction
increasing from 1.7, have given excellent
results. The best results were obt'lincd with
ball screens made of beads whose index of
refraction is between 1.8 and 1.9."). Such

 

surfaces have a reflect ing power of the order of
more than 200 times greater than that of a
white surface and the Applicant has ulrst'l ved
that in utilizing these surfaces as a projection
screen for a photographic shot, it ls-comes
very easy to obtain a projection which is
reflected by the screen without, however,
being reflected by the material obj-eta
placed in front of it, even if these objects
Coiisist of white surfaces.

The invention will be more fully under-
stood from the ensuing description with
reference to the accompanying drawing,
which shows by way of example one im-
bodiment of the invention and in which:

Fig. 2 is a sectional view of an embodiment
of the surface of the sclf-collimating screen;

Fig. 3 is a diagrammatic plan of an
embodiment of the shooting device.

With rcfercnec to Fig. 2 it is H-UJII that the
selfwollimating surface comprises a support
1 on which is applied a reflecting layer 2
in which transparent balls 3 are emls-vldtd,
for example over a part of their surface.
These balls have a small diameter, for
example of the order of 0.05 1.5 aim but
preferably t).ltt-ti.'2."i mm. These balls are
of glass or of a refractive plastic material
having a high index of n-fraction. An index
of refraction between 1.7 and 2, and, pre-
ferably, between 1.8 and 1.9.") is perfectly
suitable. for obtaining maximum reflecting
ptmt‘t'.

Above the reflecting layer, the balls are
interconnected by a binder 4 conipri-ing for
example a resin and preferably coloured
black. These balls are thus cmls-ddcd in
the layer to the extent of a little more than
one-half their surface.

“'hcn a beam of incident light impinge:
on the front semi-sphere of a spherical
self-collimator, the reflected light flux in
unequally distributed according to whether
the incident rays impinge on the pole or on a
region near the equator of the sphere, this
distribution varying furthermore with the
index of refraction ofthe material. Generally
the reflected light flux is maximum in rt'hptft'f
of the polar dome and minimum in rc-pect of
the equatorial zone. As this unevenness is
noticeable on the image obtained it may be
necessary to soften it down by varying the
reflecting power of the. rear semi-sphere,
which acts as a mirror. For this purpose.

the rear of the su-lf-collininting ball-i may he 3.

coated with a material comps-ed of layelr
having varying projs-rties of reflection dis-
posed on a support or constituting this
support. Thus there may be Used a com-
posite reflecting layer which permits
diminishing the. reflex reflecting povwr tor
the rays striking the screen pi-rpewlieulnrly
or substantially pcrpcndicnlarly. To this end
the posterior pole of the spheres may lie in a
snbjaeent. surface having a poor reflecting

.-_ y._ -

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power, on top of which is disposed a layer of
binder having a high reflecting power,
containing for example flakes of aluminium
in Mt. [war-tion. This iaycr may he “24'".
covered by a black binder which preventsi
the light penetrating the uubjaeent layers
from rc-emerging other than through the
M-lf-collilnating therea.

This description in of course not intendtd
to be Iimitative, and the sen-en may be
fortned in a dill'erent way, provided that the
m-lf-eollimating character of the unit corn-
prising the balls 3 and the reflecting element
is retained. For example, the bath unitLd by
the hinder may be tliaptist'd on a reflecting
surface and not embodied therein, or a dark
binder may be utilized for the halle, th'u
dark binder being itself reflecting by in-
corporating in it as in the ca~e of the inter-
mediate layer, metallic fltlkCh‘ in Hl-‘IX‘n-‘ihfl,
or there may be. utilized any binder covered
with a black or dark coating, etc.

The resultant. screen does not have a
black apjwarance but in merely dark gn'y
owing to the fact that the gla-<, having a
high index of refraction, producm a very
t'nllk‘itlerable parasitic reflection of the am.
bient light on the uncovered rurfate of the
balla. In order to diminish this parasitic
I‘etlt-t'tion, an anti-reflecting layer may he
advantagcously applied on the rttr‘facc of the
glam balls. The reflecting power will thereby
be slightly lllt't‘t‘tlfll‘d.

Fig. 3 whom by way of example an optical
deuce permitting use of a screen of the
kind (test ribetl above.

Reference numeral 5 designates the reli-
eollimating aereen, it the camera, 7 the
projection apparatus and 8 a person or
material object placed in front of the screen
5 and illuminated in any manner, care being
taken, however, to ensure that there is no
light. eoming from the immediate vicinity of
the camera, since tbia light is liable to be
returned by the screen and mar the pro-
jection.

'l'be axra of the camera 6 and projector 7
are (tiapost'tl for example at 90" from one
another and interptmc'l between them ii an
obliquely disposed Mini-transparent mirror
9. Owing to this arrangement the beam of
light ironing from the projector? and impin-
ging on the acct-en 5 nectmt to im-ue from the
camera (5 towards which it is returned by the
M-lf-eollimating screen 5. it in obvious that
the two apparatua ti and 7 may be reversed
relative to the semi-transparent mirror, or
may occupy in space aueh positiom that the
beam of light always appears to iv'ue from
the lens of the camera by utilizing multiple
combinationa of rellm-ting mirrors or semi-
retlecting mirrors, the projector and the
camera being placed, if desired, in parallel,
pet pcndicular or oblique punitiona. Simitarly,
the .vubject H, instead of being placed, as

warm

47

.— ._..- - _———-—....-. _-- . ~-_ ”m.-o.

illustrated, between the screen 5 and the
mirror 9, may be advantagtously placed
between the latter and the uunera it for
taking closeup shots.

In any case the beams of incident light 70
and of reflected light must appear to emanate
from the name point, which is the centre of
the aperture of the lens of one of the app-
aratus and the optical image of the centre of
the aperture of the other apjmratus. If it 75
were otherwiae the shadow east by the object.

8 on the screen 5, due to the occultation of
the incident light, would be visible from the
lens of the camera and would produce an
undesirable black ring around the object 8. 80

Other combinations of these two apparatu-
may be visualized: For example, the pro-
jector may be directed towards the ground,
the beam of light being reflected by the
mirror in a direction pandlel with the 85
optical axis of the camera.

The utilization of lenses having a variable
focal length either in the camera or in the
projector would permit obtaining impnwionn -
of approaching or receding from the subject. 90
comparable to movements termed travelling
movements in the cinema industry.

F or panoramic motion of great amplitude,

a screen of concave curved form would be
adopted, the projection being obtained by 95
means of a projector provided with a lens
pivotable with respect to itself or a lens
having a wide angle of operation or by
means of a mmbination of several tut-«iciated
projectont. In such panoramic motion the lm
camera as well as the mirror or mirrors
would be rendered movable on a special
support, so that whatever the position, the
projection light beam would always appear
optically to issue from the lens of the camera. 105

The proeexs of the invention may alao be
utilized when it is desired to eaune I material
object to appear in front. of a very bright.
background which enables a punitive film to
be used as a mask, the positive tilm being "0
obtained by printing with very sharp
contraata in which the subject ntands out In
an entirely dark silhouette on a bright
background on which there may be. applied,
in accordance with the well-known technique, "5
any fixed or animated background. In this
case. the projection onto the screen at. the
moment of taking the shot would be limited
to a beam of light.

What I claim is: If!)

I. Installation for taking mmbincd view
by still-photography, cincmattazraphy or
television, in which persons or material
objects illuminated by a source of light and
optically projected images are photographed I25
simultam-ou.~ly, comprising a camera and an
optical projector located on the same side (if
a projection screen, and an optical reflecting
device so disposed with reij-ct. to aa'
camera and projector that the virtual image 130

 

It)

48

768,394

furIm-d by mid n-flwting (lox'irc, 01' the
uhji-ctivc uf um‘ ('Hlllt’ltlh-l Milntuntiully
“ill! the Ulij(‘('ll\'(‘ 0f the other, said pro-
jt't‘ll"!. H'H‘tll living fni'mul of a layer of
slulu-ricul lu-uds mmlu «if truihpnrvnt mutm'iul
the rvur luifliun “Twirl! lwml living l'lltlu'tltlt‘d
in a ri-llrctinu layi'r “llli‘ll .~Iippui1s tlw lM'ilth‘,
this iii~t;ill.itinu living "l‘lill'-l!‘ll‘l'l7.('(l in this
llmt will tr.m.~puri-nt man-rial has u re-
fini'tinn inch-x hot “'04-" LT and 2.

2. liutullutiun as claimed in claim I,
('ll.‘ll‘:l('l('rl’I.Hl in that mid transparent mutcr-

 

inl lmn n n-frau-tiun imlcx between 1.8 and
1,95.

3. lustnllntinn as clninwd in claim 1 at 2,
clmrm'tvrizml in that mid slilioriml bonds
Imu- n iliumi-ti-r smaller than 1.5 mm.

4. Installatiun as claimed in any one of
claims l to 3, i-li;ii':ict(-i'i7.(d in that a dark
(‘Ulnlll' lviutling luyi-r is sulwrianN-d on
will ri-lli-i-tiug sulipnrting layer and lwtweon
suit] lu-mls, \tllt‘l‘l‘ll_\' said bonds are inter-
wmuwtml (in u ‘mrtiun uf their sides.

3! AR KS & CLERK.

 

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llvll'mt: l’riliti-tl fur llm' .‘l.|ji-~t}"s Stntium-ry (lllivv. liy 'rlw l'IIiVi-I‘sitivs Press. «"1957.
l’iilili~liml :it 'l‘lu- l’utc-ut Ulliw, 23, Smitlmmlilnu Buildings, lmmlun, \\'.('.‘.’, frum which
culiii-s may lu- nlitnim-d.

—.—————.‘--- ——- . .

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768,394 COMPLETE SPECIFICATION
I swam

This drawln I: a reproduction d
the Orig! on a reduced scale.

 

 

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50

Dec. 20, 1955 W. F. JENKINS 2"‘571'129
APPAPATJS FC‘R 7P5 PRODUCTION O?
CClJFOSITS FHSTC’3?.AFHIC FFFECTS
Filed NOV. 30. 1953

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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United States Patent: Oflfice

2,727,429
Patented Dec. 20, 1955

 

 

2,727,429

APPARATUS FOR THE Paonucnoat 0F
costeosrrr: PHOTOGRAPHIC EFFECTS

Will F. Jenkins, Gloucester, Va.
Application Noyentber 30, 1953, Serial No. 395,043
3 Claims. (CI. 88—16)

This application is a continuation- in part of my appli-
cation Serial No. 274,038, filed Mar. 3, 1952.

This invention relates to apparatus tor the production
of composite photographic eflects. More particularly it
relates to apparatus whereby realistic scenes may be
photographically recorded in which the building, han-
dling, and maintenance of stage scenery may be largely
dispensed with.

The handling of scenery has always been a major prob-
lem in the staging of any kind of show. The advent
of television made the problem CICD \ orse since live
scenes cannot be repeated and corrected. Furthermore
split second timing is often necessary in staging a quarter
hour or half hour television show, hence the cost of
handling scenery can be enormous. The advertiser pays
the cost of the show, but the high cost of television pro-
duction has made the medium too expensive for many
advertisers. Reduction or elimination of constructive
scenery has up to now lowered the quality of the show.
Thus the progress of television broadcasting has been
seriously impeded.

It is an object of this invention to provide apparatus
for the simplified. cheap and effician production of still
pictures, and of mation picture or television performances.
l: is a further oiiect to provide apparatus whereby un-
tux: New zany be readily and cheaply produced or.
i-m II re or television sets.

'liTIZSC objects are obtained in a surprisingly simple
and tfiiticnt manner. The apparatus of the invention
injuries at least one back-drop having a surface covered
with a reflex reflecting surface. The staging of the
show takes place on the acting-set in front of this back-
drop. One or more cameras for recording the perform-
ance are located at a convenient place in front of the
backdrop so that the lens of the camera takes in the
action on the acting-set. Two or more sheets of plane
transparent material are positioned at spaced intervals
in front of the camera lens or lenses and between the
camera and backdrop. Two projectors or more are so
located that their light first strikes the plane transparent
sheets; the light from each projector first strikes a single
plane transparent sheet. A portion of the light from
each projector is thus reflected to the reflex reflecting sur~
face that serves as a backdrop. The relative positions
of the camera or cameras, the projectors, and the plane
transparent sheets are so adjusted that the lens of the
camera or cameras receive both the reflected light from
the projectors and the light from the scene being enacted.

In the accompanying illustrative drawings:

Fig. l is a simplified diagrammatic representation of
a stage showing a single camera with two projectors and
two plane transparent sheets it. op-.-ration; '

Fig. 2 shows an alternate arrangement of the apparatus
in Fig. l, and in addition she-.vs Low additional pro-
jectors may be incorporated into the apparatus;

Fig. 3 shons two cameras in operatic.) with two pro.
jectors and two plane transparent sheets: and

lllle

fi

2

Fig. 4 shows an arrang meat utilizing a plurality of
backdrops.

Refem’ng to Fig. l two proje :tors are shown at la and
lb. The light from projector la strikes plane trans-
parent sheet Za, while light from projector lb strikes

- plane transparent sheet 2b. A portionof the light from

)5

20

30

35

40

50

60

the projectors striking the place transparent sheets passes
on through the sheets and is unuxd here. The remain~
ing portion of 'igbt however is reflected
from the plane transparent s. eets to the backdrop or
reflecting structure 3 which has an extended reflecting
surface facing the camera 4. The reflecting surface of
the refleczing structure 3 is a reflex reflecting surface of
the type described in connection with Fig. 4 of my on
pending application Ser. No. 274,638, filed March 3,
1952. Such reflex reflecting surfaces having been long
known to the art, having b1... described for instance in
Palmquist Patents Nos. 2.294.930 and 2,379,741. In
such reflex reflector screens, an outer layer of adjacent
transparent bead or sphere-like‘ .ens elements VII :h under-
lying light reflecting elements hich are in optical con-
nection therewith cause beams of light incident on the
outer layer to be refracted and reflected a s brilliant cones
of light in a lireetion gene rally coaxial with the incident
light beams ti roughout the range of angular relations
of 'he layer surface and the direczior. of the incident light
between 90' and about 50'. Any of the reflex reflector
screens operative in the manner described above may be ’
usei for the reflector surf: ICC of the re fiector structure
3 of the systems if the invention shonn in the drawing,
including the similar rrflex reflector screens shown in
Figs. 2, 3 and 4, at 3, 30, 3b and 3c.

The light from the backdrop 3 is reflected to the two
plane transparent sheets 2a and 2b. A portion of this
reflected light passes through the plane transparent sheets
and is recorded by the camera 4 which can be a still
camera, a motion picture camera. or a television camera.
The camera 4 will not record the light from the pro—
jectors that strikes the actors 5. , The actors S are diffuse
reflector r as far as the camera 4 is concerned and extra
side lighting 6 masks the projector‘s light. Hence any
images thrown by the projectors do not shout up on
the actors 5.

Fig. 2 illustrates another way to set up the apparatus
of Fig. 1. In Fig. 2 projector la is located on the other
side of the camera 4 from projector lb. Such an arrange—
ment in no way changes the operation of the apparatus
as shown in Fig. l. The sheets 20 and 2b, the projector
lb, the backdrOp with the reflex reflecting surface 3 and
the actors 5 all function as before. Fig. 2 also shows
how a third projector lc may be brought into use. in
Fig. 2 as shown projectors la and lb are each throwing
images to the backdrop 3. Prcfector lc is capped. In
order to cut out projector lb and cut in projector lc the
plate transparent sheet 2b is revolved 90’ on its vertical
axis so that it is parallel to plane transparent sheet 20.
At the same time projector le is uncapped and projector

LR: FrniaMcn

nu v»;

‘ lb is capped. By this method each plane transparent

sheet may utilize a pair of projectcrs. one located on each .
side of the sheet, and adapted to alternatively throw an
image to the backd. op 3. It mus: be pointed our that the
location of the projecrors is not critical. They may be
located above or below the plane transparent sheets. it
is only necessary that the light from each projector im-
pinge on the plane transparent sheet and then be reflected
to .he reflex surface on the backdrop. in order for the
camera to see a useable image. on the reflex reflecting
screen the projector‘s light must be focused on the screen.
The camera should be located so 1‘ .t the light pan from
the batkdrop to the camera ler .. is approximartly the
same length as the light path in: '3 the projecto- lers to
the backdrop via the plane. transparent sheet; the camera

 

 

52

$787,199

should be same optical distance from the screen as the
projector.

The use of two projectors with one camera as shown
in Fig 1 allows the'productlon of some interesting cflccts.
The background seenery may be easily changed while
the actors continue a scene. Changes are made by
turning on one projector or uncappirrg its lens at the
same time that th.‘ c'her projector is turned off or capped.
If the change is slow it amounts to a fade. If it is abrupt
it is a dissolve. Much laboratory processirc. is elimi-
nated in this way. Marry effects impossible in the lab-
oratory may now become possible, for instance, as fad-
ing a character from one scene into another. making
montages of sequential backgrounds while the actors
move uninterruptedly. One or both of the projectors
can be a morion picture projector. By masking part of
one slide in one projector and a corresponding other part
of the other side In the other projector parts of two
projections can be combined into one. For ezample
one projector may show a still slide of the interior of a
room with a window. A slide in the other projector
can then fill in the exterior view. Thus it is possible
to use a slide of a room interior with a summer scene
through the window, and later to us: the same slide with
a wirtter s:ene sisible through the window. If the pro-
jector showing the exterior scene is 3 motion picture pro-
jector it is possible to show trees blowing about, waves
in motion 01 such matter as automobiles passing by.
My combinations of the scenes from both projectors it is
also possible to show such scenes as a river flowing
through the Sahara Desert.

The projtctors may be adapted so that the slide being
used in the projector moves according to the turning
of the. camera. The slide will move Iaterally in the
projector. With this ararngement t.Ie projected image
seems to stry fixed while the camera pans.

Fig. 3 illustrates a modification of the apparatus where-
in tIIo or more proiectors may be used each with its
corresponding plane transparent sheet in conjunction with
two or urore cameras. The great significance of this
mot'ification is that the same backdrop serves two or
more of the projector-sheet-camera systems. The reflex
refl‘ ding characteristics of the backdrop are such that
the light from each projector is returned to its point of
origin with a ninirnum of straying. Thus in Fig. 3,
camera 4 and camera 40 may each record action of the
actors 5 set against a different background and the light
from projector la will not interfere with camera 4:: and
the light from projector lb will not interfere with camera
4. When the cameras are equipped with proper filters,
and are properly spaced, this arrangement can be usnd
to produce 3-dimensional shows. ‘

The. apparatus of the present invention is such that
the camera-screcn-projector system need not remain fixed
in position. The system may move in toward the actors
for close-ups and it may back off for long shots. It
may also move to one side for angle shots. As the
system moses both the camera and the projectors are
kept in focus by means well known in the art. As men-
tioned earlier the slide In a projector may be moved
laterally so that the camera sees the actors in a changing
position relative to the background. The entire system
may be mounted on a dolly for ease of movement. When
the modification as shown in Fig. 3 is used each of the
systems preferably would be mounted on its individual
dko.

Although the drawings show only two plane trans-
parent sheets with their accompanying projectors it is
entirely feasible to use 3, 4 or more place transparent
sheets each with its own projector. The intensity of a
projector's l’ght may be increased should it become neces-
sary for the light from that projector to pus through
a whole series of plane transparent sheets a: it returns
from the backdrop to the camera.

Fig. 4 illustrates an arrangement with a tluralft) of
backdrOps. The reflex surfaces can be used not only

10

15

20

25

30

t:
LI

40

.4

as the backdrop 3, but anywhere on the acting-set as
illustrated by backdrops 3a, 36, and 3:. Part of the
scenery may be projected on backdrop 3. but another
part may be projected on backdrop 30 in the middle
ground, and a third part on backdrop 3b in he fore-
ground. The necessary depth of focus for sharp pro-
jection can be had by special lens design or by stopping
down the projector aperture. Or the image from any
one projector may be confined to any one backdrop. With
bIckdrops like 30. 3b. and 3c. in use. a: actor as seen
by the camera actually disappears behind the piece of
scenery depicted by the projected image. Various props
a-Id microphones may be concealed behind any of the
additional backdrops. The backdrops themselves lire
invisible to the cameras since they merely ap;car as a
piece of scenery; an object behind them will be invisible
too. It is not necessary that the addincal backdrops
be parallel to the main backdrop 3. they may be at
any angle as illustrated by backdrop 3a.

The main backdrop 3 or any of the backdrops need
not be in the form of a plane surface. As seen by the
camera they may be concave or convex or irregular.
The reflex properties of the surface of the backdrops re-
turn incident light to its source whether or not the path
of the incident light is normal to the surface of the
backdrop.

I claim:

I. In a photographic arrangement for photographing a
performance on acfirIg-set elements situated in the front
of a background. at least one background structure having
an extended reflecting surface, at least two photographic
cameras each having its optical axis crossing said reflect-
ing surface and so positioned that the angle between the
optical axis of one camera and said reflecting surface is
different from the corresponding angle between the opti-
cal axis of the other camera and said reflecting surface
and as to record both an image fecused on said reflecting
surface and a performance on an acting-set situated be-
tween said reflecting surface and said camera lens. the ex-
terior of sand reflecting surface directly facing said earn.
eras having a light returning layer of adjacent trans-
parent minute lens elements and underlyan light reflect-
ing elements in Optical connection with said elements for

‘ causing beams of light incident on said reflecting surface

45

50

60

75

from the region facing said reflecting surface to be refract-
ed and reflected as brilliant cones of light in a direction
generally coaxial with said beams, at least one plane
transparent mirror body extending with its plane at an
angle to the optical axis of one of said cameras between
said one camera and said reflecting surface for reflecting
incident light received from a lateral direction transverse
to said one axis toward said reflecting surface and thereby
causing said so reflected incident light to be in turn re-
flected as brilliant cones of light towards said one camera.
at least one image projector for said one mirror body so
positioned relatively thereto that the projector‘s light im-
pinges on said one mirror body from said lateral direc-
tion and is focused thereby on said reflecting surface for
causing said reflecting surface to return the projector‘s
light as brilliant cones of light in the direction generally
parallel to said one optical axis towards said one camera
throughout the angular positions of said one camera to
said reflecting surface ranging between 90‘ and at least
60’. and a further sirr ilar mirror body and similar image
projector similarly pos?.ioned relatively to said other cam-
era for causing th: light from said further projector to
be returned by said reflecting surface as brillimt cones
of light in a direction generally parallel to the other opti-
cal aids toward said other camera. the angles between
said reflecting surface and said two optics] axes being
sufficiently diflerent as to cause one camera to record an
image projected on said reflecting surface by one of said
projectors and the other cameras to record an image pro-
jected on said reflecting surface by said further projector.

2. In a photographic arrangement as claimed in claim I.

 

 

53

2,727,499

5

said one camera and its associated mirror body and image
prcjec'cr having a movable common sUpporti'tg struc-
ture constituting therewith on-: camera set movable as
a unit to different photographing positions relatively to
said reflecting screen.

3. in a photographic arrangement as claimed in claim 1.
said one camera and its associated mirror body and image
projector having a movable common supporting struc-
ture constituting therewith one camera set movable as a
unit to different photographing positions relatively to said
reflecting screen. said other camera and its associated
mirror body and image projecting having anather movable
common supporting structure constituting therewith a fur-
ther camera set mcva'cle as a unit to digerent photograph-
ing positions relatively to said reflecting surface.

10

16

References Cited in the file of this patent

l,301.538
1,526,715
1,959,498
l,998,054
2,076,103
2,174,931

598,712
475,312
985,945

55,912

UNITED STATES PATENTS

 

Brainerd ............... Apr. 22, 1919
Moon et al .............. Feb. 17, 1925
Planskoy ............... May 22, I934
McBurncy .............. Apr. 16, 1935
Warner ................ Apr. 6, 1937
Terry et a1. ............. Oct. 3. 1939
FOREIGN PATENTS
Germany ............... June 18, l934
Great B'itain ........... Nov. 17, 1937
France _- -__- Mar. 21. 1951
France _ a..- June 4, 1952

 

(1st Addition to No. 985,945)

 

54

Dec. 20. 1955 w. P. JENKINS 2.727.427

APPARATUS FOR PRODUCTION OF LIGHT
EFFECTS IN COLEFOSI'I‘E PHOTOGRAPHY
Filed larch 3, 1952

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

 

 

 

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United States Patent Office

2,727,427

APPARATLS FOP. PRODUCTION OF LIGHT
EFFECTS IN COVIPOSITE PHOTOGRAPHY

Will P. Jenkins, Gloucester, Va.
Application March 3, 1952, Serial No. 174,638
8 Claims. (CI. 88-46)

This invention relates to apparatus for the production
of light effects. More particularly it relates to apparatus
for the production of television shows, or motion picture
shows. More particularly it relates to apparatus whereby
the building, handling, and maintenance of stage scenery
may be largely dispensed with.

The handling of scenery has always been a major prob-
lem in the staging of any kind of show. The advent of
television made the problem even worse since live scenes
can not be repeated and corrected. Furthermore split-

second timing is often necessary in staging a quarter-hour ..

or half-hour television show hence the cost of handling
scenery can be enormous. The advertiser pays the cost
of the show, but the nigh cost of television productions has
made the medium too expensive for many advertisers.
Reduction or elimination of constructed scenery has, up to
now, lowered the quality of the show. Thus the progress
of television broadcasting has been seriously impeded.

The prior art offers several partial solutions to the
scenery proHcm. One system has been to project a
scene or motion picture on a screen and then to photograph
a live performance against the background of the pro-
jected scene. This system is useful in some applications
but it often does not give the desired effect. Great dif-
ficulty has been encountered in maintaining the projected
scene at the necessary brilliance and sharpness and at the
sa' re time maintaining the rest of the stage-set at the de-
Pet: of illumination necessary for good photography.

Other systems use lenses and mirrors in varying arrange-
ments in order to combine a live scene with either a pro-
jsctcd scene or a miniature scene. Perhaps the most
representative of the optical systems is that disclosed
in U. 8. Patent 2,076,103 to Walter Thorner.

in the Thcrner system a projected image is reflected
from a semi-tiar-iparcnt surface. The reflected image
then strikes a large spherically-curved concave mirror
which reflects the image back through the semi-transparent
surface and focuses the image on the objective lens of a
film-containing camera. A live performance takes place
in front of the large concave mirror so the camera records
the live performance against the background of the pro-
jected image.

Althoug.. the T.iorner system serves very well for photo-
graphing short sccnes under certain conditions, it suffers
from three serious shortcomings. First, the cost of the
large-sized, optically perfect, concave mirror, is so large as
to be prohibitit r. Second, any stray light striking the con—
cave mirror 2.. reflected to various points on the acting-
set, thus the lighting of the live performance becomes a
serious problem. Third, and perhaps most important,
neither the camera: nor the projector can be moved away
from the focal point of the mirror; the position of both
camera and projector are rigidly fixed at the focal point
of whatever concave mirror is in use. Now in the staging
of most performances it is essential that the camera have
a certain freedom of movement. if viewer-interest is to be
maintained the scene mus. not become monotonous; it

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Patented Dec. 20, 1955

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must vary. Further, the build-up of suspense, the urbane»
ing of dramatic values, and the emphasizing of certain
characters, depends largely on the camera‘s ability to move

in and out for close-ups and long shots, and to take up -

positions that will produce a maximum emotional impact
on the viewer. A rigidly fixed camera can destroy what-
ever merit lies in a given scene. The talents of direaa
and cameraman in trying to achieve the desired effect:
are largely rendered nugatory.

Accordingly, it is an object of this invention to provide
apparatus whereby the above-mentioned shortcomings of
the prior art are overcome.

it is a further object to provide apparatus for the
simplified, cheap, and efficient production of motion piov
ture or television performances.

It is a further object to provide apparatus whereby nnr
tz<uai effects may be readily and cheaply produced on
motion picture or television sets.

Other objects will appear in the following description.

The apparatus, in accordance will the invention, in-
cludes at least one backdrop including a directionally re-
flecting surface known as a reflex light reflector. The
staging of a show trlzes place on the acting-set in front
of this backdrop. A camera for recording the per-
formance is located at a convenient place in front of
the backdrop. A sheet of plane transparent or semi-
transparcnt material is positioned in front of the camera
lens and between the camera and backdrop. A projector
is so located that its light fist strikes the plane transparent
sheet. A portion of the light from the projector is thus
reflected to the reflex reflecting screen that serves as a
backdrop. The relative positions of the camera, the pro-
jector, and the plane transparent sheet are so adjusted
that the lens vf the camera receives both the reflected light
from the projector and the light from the scene being
enacted.

in the accompanying illustrative drawings.

Fig. l is a perspective view of a stage on which one

arrangement of the apparatus of the present invention is.

shown in operation;

Fig.2 is a diagrammatic representation cf the stage

showing the apparatus employed to its ssimolest form;

Hg. 3 is a diagrammatic representation showing an—
other modification of the apparatus;

Fig. 4 is an enlarged section of the reflex reflecting screen
show ing the preferable type of reflecting units;

Fig. 5 is a diagrammatic representation showing an-
other modification of the apparatus.

In all of the drawings the reflex reflecting screen is at I.
Since this screen constitutes an essential feature of the in-
vention, and since the surprisingly great versatility of the
present system depends on this screen, it will be dimmed
in some detail.

The screen should be large enough to encompass what-
ever projected background is desired. In some cases the
sereen may be long enough to serve as a backdrop for

two or more adjoining sets; this application will be do. ‘

cussed later. If the screen is built so as to be flexible it
will merely hang in the same way as any other flat cur-
tain. Supports for the screen are not shown in the draw-
"‘83-

The screen is so constructed that any light that strike: it
is reflected back to the source. This can be accom-
plished in several wavs. Fig. 4 shows an enlarged sec-
tion of the screen illustrating the preferable way in which
this can be done. Clear glass or resinous heads 9 d
suitable index of refraction are imbeddcd in a binder
coating 10. A reflector coating 11 refreCts incident light
rays 7 back through the retracting glass heads 9 to tin
source as shown by reflected ray 6. The back coating 11
strengthens the screen. Such a catadioptn’c system will
return both paraxial and normal rays to their team

j‘e

 

Construction details may be varied to achieve maximum
reflex reflection brilliancy consistent with wide angularity.
Since the glass or resinous beads 9 can measure about 3
'9 l0 mils in diameter there are over 10,000 of them per
square inch of screen surfaCe.

Screens of the type described above in connection with
Fig. 4, have been long known inthe at as reflex re-
fleCtor screens. having been described, for instance, in
Palmquist Patents Nos. 2,294,930 and 2,379,741. In such
reflex reflector screens, an Outer layer of adjacent trans~
parent head or sphere-like lens elements with underlying
light reflecting elements which are in optical connection
therewith cause beams of light incident on the outer layer
to be refracted and reflected as brilliant cones of light
in a direction generally coaxial with the incident light
beams throughout the range of angular relations of the
layer surface and the direction of the incident light be-
tween 90' and about 50°. Any of the reflex reflector
s'. .ecns opcrathe in the m..nncr described aoove may be

used for the reflector surface of the reflector structure 1 ‘

of the system of the invention.

In Fig l, the projector 3 throws light on a sheet of
plan: transparent or semi- -transparent material 4. A por-
tion of the light passes right through the sheet and is un-
used in this arrangement. The remainder of the light
however is reflected to the reflex reflecting screen I. With
the proper focus on the projector 3 an image will be
formed on the screen 1. This image will appear clear and
sharp to the camera 5 since the camera 5 is positioned to
the rear of the sheet 4 and is located near the apparent
source of light from the projector 3. Thus the actors 2
can be photographed in action against whatever back-
ground scene is desired. The light reflected from sheet 4
does not adversely aflect the photography of the actors
2 even though the light strikes the actors 2 on the side that
is being photographed. The light is not in sharp focus
on the actors 2 and is dillusedly reflected frcm them.
Hence the efl’ect of this re “ected light is negligible; in
practice it is unnoticeable.

The apparatus functions just as well when the projector
3, the sheet 4, and the camera 5 move in toward the
actors 2 for a close-up, or back away from the actors 2
for a long shot. The focus of projector 3 and camera
5 are easily adjusted by means well-known in he art. If
a projector possessing a considerable depth of focus is
used, it may be unnecessary to vary the focal adjustment
of the projector at all. In any case the image reflected
from the screen 1 presents a startling illusion of depth.
Thus the actors 2 appear to perform in the midst of ac—
tual scenery.
the camera 5 are all shown mounted as a unit on the dolly
15. Hence close-ups, long shots, and angle shots may
readily be taken withou‘ interrupting the pi otography.

Under some conditio is it may be no cess: try to prevent
the back side of the plane transparent sheet 4 (the side
nearest the camera 5) from receiVing extraneous light
from Other portions of the set. This can easily be done
when necessary by putting up a curtain or drop to block
off stray light.

Not only may the camera 5 move in and out from the
screen 1 in accordance with the present system. it may
also move to one side or the other for angle shots. Thus
the camera 5 records excellent scenes when light reflected
from the sheet 4 strikes the reflex reflecting screen 1 at an
angle of~-.’0' to the normal. Even greater angles may be
Used but care must be taken not to exceed the angle at
which the brilliancy of the reflected image falls below that
required for good photography. This maximum angle
depends on the characteristics of the particular reflex re-
flecting screen in me; it usually runs around 40‘ to nor-
mal.

The apparatus of the present invention possesses an-
other important .13. .-antage. fig. 2 is a diagrammatic plan
view of Fig. l, showing the employment of stage lights 13.
The lights 13 may be used freely as the director sees fit

in Fig. l the projector 3, the sheet 4, and -

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4

since they will not auversely affect the photography no
long as they do not shine directly into the objective lens
of the camera 5. Light from the stage lights 13 that
strikes the reflex reflecting screen 1 will not be reflected to
the camera 5, but rather back tothe stage lights 13.
Light Striking the sheet 4 will not be reflected to t' at por-
tion of the screen 1 that is being photographec by the
camera 5. Thus in addition to reducing the problem of
handling scenery, the present invention does away with
many lighting problems.

Fig. 3 is a diagrammatic plan view showing the appao _
ratus of the present invention set up in a modified ar-
rangement that utilizes the entire beam from the projector
3, instead of merely a p: rtion. The screen I, projector
3, sheet 4, and camera 5, function in the same wry as
described before. in addition a smaller reflex reflecting
screen 1' reflects an image focused on it by lens 5'. Th"
image originates from the unreflected light that passes
through sheet 4 from the projector 3. Thus the camera
5 sees two matching images, a large one from the. acting-
set screen 1 and a small one from the miniature-set screen
1'. If necessary, the brightness of the two images may
be matched by means known to the art.

With such an arrangement it becomes possible to
achieve unusual realism without resort to the
handling of scenery. For example shutters l4 mask the
left-hand quarter of the actingvset and the right-hand
three-quarters of the miniature set. lnstead of the shutter!
14 as shown it may be advisable to position biack masks
directly over the surface of screens 1 and 1'. In this
way a sharp dividing line may be obtained in the final
composite image. The camera 5 still sees a complete
set. The dividing line between the two scenes that make
up the composite image may be the projected image of.
say, a doorway seen from an angle. Now an actor 2
positioned on the portion of the acting—set masked by
shutters 14 will be invisible in the composite image until
he walks over to the unmasked portion of the acting-set.
When ‘ne does so he will appear to have entered the set
through the door. The shutters 14 may then be shifted
to fully expose the acting-set and completely mask the
miniature-sea. The actor may then return to his original.
position, only this time he will appear to be in front
of the door through which he has just entered. Thus
realism is obtained without the necessity of constructing
a room complete with doors. At the same time appro-
priate props like desks, chairs, tables, beds, and the
like. may be placed on 'he acting-set as part of the scene
whenever necessary. Since these objects are difluse re-
flectors the light reflected from sheet 4 does not cam
the objects to look mottled when photographed by the
camera 5.

In similar fashion it is possible to obtain a composite”
image made up of the top portion of the miniature-set and
the bottom portion of the acting-set. in fact any por-
tion of the acting-set can oe masked so long as the corre-
sponding portion of the miniature-set is unmasked. Thus
if it is desirable to show an actor going behind a building
and coming out on the other side, the central portion of
the acting- -set can be masked while the miniature-set
supplies the image of the building that apparently oc-
cupies the masked portion of the acting-set. Many other
modifications will be obvious to those skilled in the art.
Suitable shutters may be installed whenever the matching
of opposing portions becomes desirable.

The addition of a miniature-set as described above in no
way affects the ability of the camera 5 to move to the
most suitable position; close-ups, long shots, and angle
shots can still be taken. For this purpose it may be well
to have the projector 3, sheet 4. camera 5, lens 5', minia-
ture-set l', and shutters 14, all mounted on the same dolly.
Thus the installation can move as a unit
‘ if desired, the screen 1' may be the same size as the
screen 1. and located the same distance from sheet 4 as is
screen 1. The lens system 5' thus becomes unnecessary.

 

5

Two full-size acting-sets become available, one in front
of screen I and one in front of large-size screen 1'.
This arrangement may be particularly desirable Where
weird effects are needed as in the production of a science.-
fiction shown. For example, performers can be shown
to walk through one another.

Fig. 5 shows two other modifications of the apparatus
of the present invention. Reflex reflecting screen 1" may
be positioned a: a wrng partly in front of the reflex re-
fleeting screen I; both screens are of the same construc-
tion. An actor 2 will be unseen until he steps out from
behind screen 1". Such an arrangement provides still
another method that enables an actor 2 to enter the acting-
set through a projected door, l2. which case the projected
door should coincide with the on-stage end of screen 1".
Projector 3 should have sufficient depth of focus so that
the images reflected from screens 1 and l" are matching
in clarity and sharpness.

At the same time that projector 3 is supplying a back-r

ground scene visible to the camera 5, projector 3' may
also supply a different background scene. Since the light
from projector 3' strikes the sheet 4 at an angle difl‘erent
from that of projector 3, the camera 5 will not see the

image from projector 3' unless the camera 5 shifts its

position relative to sheet 4, that is, unless the camera 5
rotates counterclockwise on its vertical axis. Thus an
actor may perform against the background of an image
from projector 3. He may then' move along the set
parallel to screen I and away from screen 1". The
camera. 5 rotates independently to keep him in view.
When the actor 2 reaches the prOper position the camera
5 will see the actor against the background of an image
from projector 3' instead of from projector 3. Thus the
set has been changed with a minimum of effort and ex-
pense. The camera 5 has beer. continuously trained on
the actor: there is no necessity for a fade-out.
Although Fig. 5 shows the projectors 3 and 3' posi-
tioned to the left of camera 5 they need not be placed
there. A projector may be positioned anywhere on the
set so long as sheet 4 is so located that the projected
image appearing on screen 1 can be seen by the camera
5. A projector may be positioned near one end of screen
1. or at the top of screen 1 for that matter. If a battery
of projectors is used each projector of necessity must be
located at a different position just off-stage from the
acting-set. The apparent distance between a projector
and the image on the reflex reflecting screen should be
approximately the same as the actual distance between
the camera and the image on the reflex reflecting screen.
A projector in the apparatus of the present invention
may be of any convenient type. in its simplest form it
may simply be a source of light, as when a performance
against a gleaming background is desired. A projector
may also consist of either a still or motion picture pro-
jector, depending on the type of background desired.
The projector may contain means for the rapid changing
of the slides to be projected as scenery. The slides can
be changed sufficiently rapiuly that a viewer is not aware
of the change until it is an accomplished fact. Thus, if
necessary, as the projector, camera, and plane transparent
sheet move forward for a close-up the slides may be
changed to show a successively smaller area of the same
background scene. In this way prOper perspective is
maintained; the size relationship between the actors and
the projected background scene is maintained at a prOper
ratio. The projector may also contain means for varying
the angularity of the slides, that is, the slides may be
partially rotate-d around their vertical axis in order to
prevent fuzziness around the edges of the image on the
reflex reflecting screen when the projector throws an image
to the screen at an angle thereto. Or a projector may
consist of a television tube confronted with a lens system
to focus the tube's image on the reflex reflecting screen.
By "television tube,” as used in the claims, is meant the
type of cathode-ray tube commonly used in television re-

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ceivers. By means of this last arrangement a composite
picture can be made up from two distinct sets on end of
which action or movement takes place. By way of ex-
ample, one television camera may be focused on a bowl
of Later into which has been dropped some solid carbon
dioxide. The resulting dense “bite fog will appear on
the televisi )n tube. that serves as a projector for the preeern
invention. Titus Lhe actors on the acting-set can be photo-
graphed in the midst of a swirling fog by using the u-
rangement illustrated in _Fig. 3; the shutters 14 are un-
necessary in this application.

The plane transparent sheet in the apparatus of the
present invention may be of any convenient size. A‘
too-large sheet works no hardship since the portionnot
used for reflection does not interfere with operations.
The sheet may be made of glass or suitable resinous mate-
rial. Although preferably the sheet is perfectly trans-
parent it may be lightly silvered so as torender it semi-
transparent. In fact if a projector is positioned. near the
center and top of ' the reflex reflecting screen the sheet
should preferably be lightly silvered in order to reflea
sufficient light to form an image on the reflex reflecting
screen. Any suitable means may be used for holding the
sheet in the desired position; adjustable or fixed meant:
may be employed. It a thick sheet is used one race of
it may be coated with a nan-reflecting coating to avoid
the possibility of a double image, although this difficulty .
has not been encountered in practice. The phrase “plane
transparent sheet" as used in the claims is meant to in-
clude a plane semi-transparent sheet. ' ‘

Several types of cameras may beused in the present
invention. A still picture camera can be used for the
taking of publicity or advertising stills. A mation pic-
ture camera can be used and the film that is obtained can
be later displayed in the usual way either in a motion pic-
ture theater or in a television broadcast. Or the camera
may be a television transmitter that instantly televisee
the scene being photographed. The phrase “camera hav-
ing an objective lens" as used in the claims is meant to
include a television transmitter, in motion picture camera,
and a still picture camera.

in some applications of the present invention it may be
expedient to exchange the positions of the camera and
the projector. With this arrangement the projector throws
an image through the plane transparent sheet and on to
the reflex reflecting screen. The camera then photo-
graphs the image that is reflected to it by the plane trans-
parent sheet. Since the camera ean also see through the
plane transparent sheet, a blank drop of some kind may
be positioned in the camera's line of sight beyond the
plane transparent sheet when a miniature-set is not in
place. ‘

The composite images obtained by the apparatus of
the present invention are blended optically, not elec-
tronically, thus eliminating the disastrous phenomenon
known as halo. The composition of the final image I:
completely under the control of the cameraman who is in
the best position to exercise judgment as to the merits of
the final image. -

Further applications of the present invention may readily
be found without departing from its spirit and scope.
The versatility of the invention allows nume°ous embodi-
ments, therefore the invention should not be limited by
the specific applications described herein, but only by the
appended claims.

I claim:

I. In cornbi'ration: at least one reflecting structure havo
ing an extended reflecting surface, a camera having an
objective let 5 with an Optical axis crossing said reflecting
surface and so positioned as to simultaneously record
both an imrg; focused on said reflecting surface an' an
image of a performance or. an acting-set situ. ted between
said reflecting surface and said camera, a substantially
plane transparent mirror body extending at an angle to
said optical axis between said camere and said reflecting

58

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7
surface for reflecting incident light received from a lateral
dirccuon transverse to said axis toward said reflecting
surface, at least one image projector so positioned that
the pr‘ojector's light impinges on said mirror body from
said lateral direction and is focused by said mirror body
on said reflecting surface, and an acti 1g set situated be-
tween said reflecting surface and said mirror body. the
exterior of said rtfleeting surface directly facing said
camera having a light returning layer of adjacent trans-
parent mihure lets elements and underlying light reflect-
ing elements 1" Optical connection with said lens elements
for Causing be ms of light from said projector incident on
said layer to be refracted and reflected as brilliant cones
of tight in a direction generally coaxial with said beams
toward said camera for causing said camera to record
said brilliant cones throughout the angular positions of
said reflecting surface rel: tively to said optical axis rang-

ing between 90' and at least 60'.

in the combination as claimed in claim 1, a further
reflecting structure having a further reflecting surface of
similar light reflecting properties as said extended reflect-
ing surface and positioned to receive light of said pro-
jector passing through said transparent mirror body and
arranged to reflect received light back onto said minor
body, said camera having an objective lens system ar-
ranged fo record a composite image comprising a pet'-
formance taking place on said acting-set and the projected
light reflected by said two reflecting surfaces.

3. 1n the combination as claimed in claim 2, a further
aeting-5°t positioned between said mirror body and said
further reflecting surface, said camera having an objec-
tive lens system arranged to record a composite image
comprising performances taking place on said two acting-
sets and the projected light focused on said two reflecting
surfaces.

:. 1n the combination as claimed in claim 1, a further
reflecting structure of substantially smaller size titan said
one reflecting structure having a further reflecting surface
of similar light reflecting properties as said extended re-
flecting surface, a lens arrangement positioned between
si‘d min 0. body and further reflecting surface for focus-
iag a portion of the projected light passing through said
mirror body onto said further reflecting surface, said
camera hav ng an objective lens system arranged to record
a composite image comprising a performance taking place

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on said acting- set and the projected light reflected by said
two reflecting surfaces.

5.1r the combination as claimed in claim 1, a further
reflecting structure of sul'stantiallg smaller size than said
one reflecting structure having a further reflecting surface
of similar light reflec1ir.g properties as said extended re-
flecting surface, a lens arrangement positioned between
said mirror body and said further reflecting surface for
focusing a portion of the projected light passing through
said mirror body onto said further reflecting surface, a
miniature-set poshioned between said lens system and said
further reflecting surface first masking elements arranged
to mask; portion of said acting-set, further masking ele-
ments arranged to mask that portion of said miniature set
that corresponds to the unmasked portion of said acting-
set, said camera having an objective lens system arranged
to record a composite image comprising performances
taking place on said acting-sets and the remaining pro-
jected light focused on said further reflecting screen.

6. The combination according to claim 1 wherein the
said projector comprises a motion picture projector. .

7. The combination according to claim 1 wherein the
said projector comprises a still picture projector.

8. The combination according to claim 1 wherein the
said projector comprises a television tube confronted by
a lens system.

References Cited in the file of this patent
UNITED STATES'PATENTS

1,122,192 Clark ................. Dec. 22. 1914
1,150,869 Lewin ........ - ....... Aug. 24, 1915
1,301,538 Brainerd .............. Apr. 22, 1919
1,418,033 Sutcliffe ............... May 30, 1922
1,526,715 Moon et al. ............ Feb. 17, 1925
1,636,112 Schufltan .............. July 19, 1927
1,720,232 North .................. July 9, 1929
1,806,864 Pallemaerts ............ May'26.‘ 1931
1,998,054 McBurney ............. Apr. 16, 1935
2,076,103 Thorner ................ Apr.6, 1937
2,169,045 Haskin ................. Aug. 8, 1939
2,553,903 Dufour ................ May 22,1951

FOREIGN PATENTS
598,712 Germany .............. June 18, 1934
475,312 Great Britain .......... Nov. 17, 1937

APPENDIX IV

DRAWINGS OF PROJECTION STAND BUILT

IN HAGERSTOWN

59

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APPENDIX V

THE ACCOMPANYING FILM

65

 

 

THE ACCOMPANYING FILM

The film that accompanies this written portion of
the thesis is entitled "MASKS". It is one of the final
lessons filmed in the series done for the Title III ETV
project. It is the first and only lesson filmed on the
front screen projection system.

There are some obvious production problems. We
had very little time to produce the lesson, and we were
just beginning to learn how to use the front screen system,
which still had some bugs to be worked out. But it
clearly demonstrates some of the potential of front screen
projection. It also demonstrates a few of the problems
discussed in the thesis.

The important thing to remember is that the costs
were not prohibitive. The whole system, less camera and
projectors, was in operation for under $1600. Equipment
to achieve comparable quality in rear screen projection,
even if we had had the studio space for rear screen work,
would have been significantly higher.

Front screen projection allowed us to present

material in a manner that would have otherwise been

66

 

 

 

 

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67

possible only through the use of rear screen projection or
a matt process, neither one of which was available to us in
Hagerstown. It allowed us to present information in a
creative and informative way that broke away from cliched

traditional methods, and at a cost that most small producers

could manage.

 

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APPENDIX V

THE ACCOMPANYING FILM

65

 

 

II!“II|‘[

THE ACCOMPANYING FI LM

The film that accompanies this written portion of

the thesis is entitled "MASKS". It is one of the final

 

lessons filmed in the series done for the Title III ETV
project. It is the first and only lesson filmed on the
front screen projection system.

There are some obvious production problems. We

 

had very little time to produce the lesson, and we were
just beginning to learn how to use the front screen system,
which still had some bugs to be worked out. But it
clearly demonstrates some of the potential of front screen
projection. It also demonstrates a few of the problems
discussed in the thesis.

The important thing to remember is that the costs
were not prohibitive. The whole system, less camera and
projectors, was in operation for under $1600. Equipment
to achieve comparable quality in rear screen projection,
even if we had had the studio space for rear screen work,
would have been significantly higher.

Front screen projection allowed us to present

material in a manner that would have otherwise been

66

 

67

possible only through the use of rear screen projection or
a matt process, neither one of which was available to us in
Hagerstown. It allowed us to present information in a
creative and informative way that broke away from cliched

traditional methods, and at a cost that most small producers

could manage.

 

 

 

Ill-r“. {it"s ['1 it

SALES,

APPENDIX VI

RENTAL, AND PRODUCTION COMPANIES

68

 

 

 

Sales:

SALES, RENTAL, AND PRODUCTION COMPANIES

TELESYNC CORPORATION
20 Insley Street
Demarest, New Nersey 07627

CO/AX GRAPHIC SYSTEMS LTD.
902 Wentworth Avenue
North Vancouver, B.C.
Canada

Rental or Sales:

 

FRONT PROJECTION COMPANY
6647 Matilija Avenue
Van Nuys, California 91405

Production Companies:

 

CALVIN PRODUCTIONS/CALVIN CINEQUIP, INC.
1105 Truman Road
Kansas City, Missouri 64106

THE JAM HANDY ORGANIZATION

2843 East Grand Blvd.
Detroit, Michigan

69

 

 

I. -‘~ {4 ‘-I-- AJ-A uTfi j

 

 

BIBLIOGRAPHY

7O

BIBLIOGRAPHY

Books

American Cinematographer Manual. Third Edition. Edited
by Arthur C. Miller, A.S.C., and Walter Strenge,
A.S.C. (American Society of Cinematographers).
Hollywood: Gardner/Fulmer Lithograph, 1969.

 

Clark, Frank P. Special Effects in Motion Pictures.
Society of Motion Picture and Television Engineers,
Inc. Easton, Pennsylvania: Mack Printing Co.,
1966.

 

 

Fielding, Raymond. The Technique of Special-Effects
Cinematography. Communication Arts Books.
New York: Hastings House, 1965.

 

 

Kingslake, Rudolf. Lenses in Photography. New York:
A. S. Barnes and Co., 1944.

 

Langford, Michael J. Basic Photography. Amphoto. London:
The Focal Press, 1970.

 

Articles in Periodicals

 

"A Double Front Screen Projection Set-up that Uses Slides
for Backgrounds." American Cinematographer
(April, 1970), pp. 340, 369.

 

Palmquist, Philip V. "Retro—Reflective Screen for Reflex
Projection Composite Photography." American
Cinematographer (July, 1969), pp. 688—690.

 

 

Rider, L. F. "The Alekan-Gerard Process of Composite
Photography." American Cinematographer (July,
1962): PP. 428, 431-432, 434.

 

71

 

72

Unpublished Material

 

Minnesota Mining and Manufacturing Company Product Bulletin.
Remote Sensing Systems, "SCOTCHLITE" Brand High
Gain Reflective Sheeting #7610, March, 1971.

 

 

Instructions for the Operation of a Retro-Reflective Front
Screen Projection System, prepared by the Telesync
Corporation, 20 Insley Street, Demarest, New Jersey,
07627. (Mimeographed.)

Other Sources

 

Letter from Mr. Bob Swanson, Telesync Corporation, 20
Insley Street, Demarest, New Jersey, 07627, to
Mr. Blair L. MacKenzie, Title III ETV Project,
Washington County Board of Education, Hagerstown,
Maryland, 21740, December 26, 1969.

Public Documents

 

United States Patent Office, Washington, D. C., 20231.
List of relevant patents for those interested
in further research into this area. Those patents
included in the thesis are indicated below by an
asterisk.

3,350,980 . . . November 7, 1967. G. D. Margolin,
Photographic Apparatus.

 

3,227,509 . . . January 4, 1966. H. Baker.
Device for Projection and Photographygof
Backgrounds.

 

2,772,600 . . . December 4, 1956. J. B. Walker,
Image Superimposition Apparatus.

 

*2,727,429 . . . December 20, 1955. W. F. Jenkins,
Apparatus for the Production of Composite
Photographic Effects.

 

*2,727,427 . . . December 20, 1955. W. F. Jenkins,
Apparatus for the Production of Composite Effects.

2,553,903 . . . May 22, 1951. A. P. Dufour,
Devices for Obtaining Composite Photpgraphs
and Motion Pictures.

 

2,169,045 . . . August 8, 1939. B. C. Haskin,
Composite Photography.

 

 

73

2,076,103 . . . April 6, 1937. w. Thorner,

Apparatus for ProducingpCinematographic Combina-
tion Films.

 

 

1,998,054 . . . April 16, 1935. J. D. McBurney,

Cinema Screen.

 

1,959,498 . . . May 22, 1934. L. Planskoy,

Production of Composite Motion Pictures.

 

1,720,232 . . . July 9, 1929. H. D. North, Light

Reflecting Screen and Process for Making the
Same.

 

1,636,112 . . . July 19, 1927. E. Schfifftan,

System of Taking Photpgraphic and Cinematographic

 

Pictures.

 

1,418,033 . . . May 30, 1922. G. H. Sutcliffe,
Means for Taking Photographs with Special Scenic
or Background Effects.

 

 

*British Patent #768,394 . . . February 13, 1957.

Henri Albert Alekan, Improvements in and Relat-
ing to Apparatus for Taking Composite Pictures
by Photography or Television. Available from
the United States Patent Office.

 

 

 

 

IL“