Improvements in Taking and in Projecting Photographic Images, in Means therefor, and in Photographic Negatives.
Year: 1898

page_text: Date of Application, 14th Oct., 1898
Complete Specification Left, 14th July, 1899-Accepted, 14th Oct., 1899
Improvements in Taking and in Projecting Photographic Images, in
Means therefor, and in Photographic Negatives.
I, WILLIAM FRIESE-GREENE, of 39, King's Road, Chelsea, in the County of
London, Photographer, do hereby declare the nature of this invention' to be as
follows:-
-
The primary object of my invention is to produce photographic negatives
containing vibrations of the various colors existing in the original scene or
picture (in other words negatives containing these various colors in a latent
state) and to reproduce the scene or picture from the negative upon a screen or
the like in the natural colors.
I effect this object chiefly by. means of a special lens hereinafter described in
the camera or photographic apparatus and by means of a similar special lens in
the magic lantern or projecting apparatus; or instead of the special lens I may
alternatively employ in both the camera and the lantern a special disc as herein-
after described in combination with an ordinary lens.
The special lens is composed of several lens sectors (say three) having one
common centre. These lens sectors are colored in separate colors preferably
blue, green and red respectively, but other colors may be adopted as for example
blue, red and yellow. The respective sizes of the sectors will differ considerably.
The green sector should be about half the size of the red sector and the blue
sector very much smaller than the green. The proportions should to some extent
depend upon the particular kind of sensitive film employed but should be chiefly
regulated according to the length of exposure required for photographing the
several colors, an important point being that all the colors shall have an equiva-
lent amount of exposure, having regard to the fact that blue requires much less
exposure than green, and green less exposure than red.
My improved lens may be used in place of the three separate lenses now in
use for color photography thereby producing one negative in lieu of three
negatives. The negative image obtained will contain vibrations, not only of
the three colors of the lens sectors but of all the varieties of color caused by the
blending of these 3 colors. For some purposes the lens sectors may have slightly
different foci.
Instead of a lens composed of differently colored lens sectors as hereinbefore
described I may employ an ordinary lens and use in conjunction therewith a
disc of suitable translucent material and colored in sectors like the lens herein-
before described. In taking a photograph this disc is caused to revolve with more
or less rapidity, the several colored parts of the disc passing successively in front
of the lens during one and the same exposure.
In projecting the image upon a screen a lens composed of sectors similarly
colored to those of the lens used in taking the photograph is employed. The
picture appearing on the screen will show all the colors of the original scene or.
picture. Or when the negative has been produced by means of a colored revolving

page_text: disc in conjunction with an ordinary lens as above described the projecting
apparatus will contain a similarly colored revolving disc in conjunction with
an ordinary lens.
Each colored lens sector or each colored part of the disc whether in the photo-
graphing or in the projecting apparatus may be made up of several small sectors
so that the size of each colored division may be increased or diminished in pro-
portion to the others in case the particular kind of film to be used or other reason
may render this change desirable.
If it is not required to obtain a picture which is colored I employ a lens com-
posed of several uncolored lens sectors having one common centre and they should
be of equal dimensions. The negative obtained bears, as is the case when colored
lens sectors are used, as many pictures as there are sectors, these pictures being
as it were superposed, the result being that the positive picture subsequently
produced is softened, and 're-touching" becomes practically unnecessary.
The invention includes the improved photographic negatives herein before
described that is to say one negative containing vibrations of the dinerent varieties
of colors of the original scene or picture.
D
AL
101 1
"
1900
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
Improvements in Taking and in Projecting Photographic Images, in
Means therefor, and in Photographic Negatives.
I, WILLIAM FRIESE-GREENE, of 39, King's Road, Chelsea, in the County of
London, Photographer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:
This invention relates to taking photographic negatives and to projecting
transparencies obtained from such negatives, and it has for its primary object to
produce photographic negatives containing in a more or less intermingled state
vibrations of the various colours existing in the original scene or picture (in
other words, negatives containing these various colours in a latent state) and to
reproduce the scene or picture upon a screen or the like in the natural colours
from a transparency obtained from the negative.
According to this invention a photographic negative of a scene or picture is
taken by means of a camera or photographic apparatus through a transparent
material or medium bearing three or more primary colours. The negatives thus
obtained will contain vibrations, not only of the several colours employed, but also
of all the varieties of colour caused by the blending of these colours. Then by
obtaining a transparency in the usual way from this negative and projecting
the image from the transparency upon a screen by means of a magic lantern
or projecting apparatus through a transparent medium coloured and constituted
similarly to the transparent medium employed in taking the negative, the image
appearing on the screen will show all the colours of the original scene or picture.
The invention allows of taking and of projecting animated or changing scenes
as well as scenes of stationary objects.
The transparent medium which I prefer to employ consists of a disc of glass
or suitable material composed of differently coloured sectors. In taking a photo-
graphic negative or in projecting a transparency obtained from such negative,

page_text: this disc is caused to revolve rapidly in front of or behind the ordinary lens of
the taking or projecting apparatus, or between the lenses when more than one
lens is employed, the several coloured parts of the disc moving successively past
the lens during one and the same exposure..
I may also employ instead of the revolving disc, a band or strip of suitable
transparent material bearing the three or more primary colours in regular repeated
succession, caused to travel rapidly in front of or behind the lens. Or I may
construct the coloured disc above referred to in the form of a lens composed of
differently coloured lens sectors having a common focus. In this last case, the
lens is used alone and in place of the ordinary taking or projecting lens.
By these means I obtain a single negative or transparency instead of the three
negatives or transparencies hitherto required in colour photography.
In the accompanying drawings,--
Figure 1 is a side elevation partly in section of a photographic camera adapted
for producing a negative according to this invention.
Figure 2 is a front end elevation of the same.
Figure 3 is a side elevation on a larger scale of the revolving coloured disc
in its preferred form of manufacture.
Figure 4 is a cross section of the same on the line IV-IV of Figure 3.
Figure 5 is a side elevation illustrating a modified form of the coloured disc.
Figure 6 is a cross section of the same on the line VI VI of Figure 5.
Figure 7 is a side elevation of a magic lantern or projecting apparatus adapted
for projecting coloured pictures
Figure 8 is a front end elevatording to this invention.
of the same.
Figure 9 is a front elevation of a lens mounted in its holder, said lens being
composed of differently coloured lens sectors according to this invention.
Figure 10 is a cross section on the line X-X of Figure 9.
Referring first to Figures 1 and 2 the photographic camera therein shown is
constructed in substantially the usual manner and comprises the objective piece 1,
front 2, bellows 3, rear part 4, and back 5, mounted on the base 6. 7 is the
objective, consisting in this arrangement of an ordinary lens. A horizontal
axle 8 carried in a bearing bracket 9 fixed to the camera front 2 extends through
the latter into the interior of the camera where it is provided with a rotary disc 10
constructed as hereinafter described, and arranged to be rotated rapidly behind
the objective.. The rotary motion can be imparted to the disc 10 in any suitable
manner. In the particular arrangement shown there is fixed upon the outer end
of the axle 8 a small cord pulley 11 which is driven by means of a cord 12 from
a considerably larger cord pulley 13 rotated by hand by means of the handle 14.
The pulley 13 is carried by a projecting part 15 fixed to the camera front 2. The
aforesaid disc 10 which is shown more fully in Figures 3 and 4, consists of a rubber
ring 11 formed with three radial strips 12 and a central boss 13 and which is
adapted to be clamped fluid-tight between two circular plates 14, 14 of colourless
glass or other transparent material by means of two peripheral flanges 15, 15
through which pass a number of tightening screws 16. A fluid tight joint at
the boss 13 of the rubber ring is further ensured by means of two plates 17, 17
which are clamped against the outsides of the glass plates 14, 14 by means of a
nut 18 screwing on a hollow bolt 19 formed with a head 11". Rotary motion is
imparted from the cord pulley 11 through the axle 8 by keying the bolt head 11ª
on the axle 8. The bolt head 11" is preferably formed as a cord pulley as shown,
so that when it is desired to arrange the disc 10 in front of the objective, the said
disc can be driven directly from the cord pulley 13 by means of the cord 12
passing around the grooved bolt head 11".
The space comprised between the ring 11, its boss 13 and the glass plates 14, 14
is divided by the three radial strips 12, into three compartments of sector shape
which are filled respectively with liquids of separate colours, preferably blue,
green and red, but other colours may be adopted as for example, blue red and
yellow. Each compartment can be filled through a hole normally closed by a

page_text: plug 20; the air displaced by the liquid escaping through a hole normally closed
by a plug 21. The actinic effect of the exposure of the colors can be varied
by varying the intensities of the colors.
Instead of making the three sectors containing the three differently coloured
liquids of equal area, and varying the actinic effect of the exposure of the colours
by varying their intensities, I may employ liquids of uniform intensity of colour,
and vary the exposure by varying the arears of the sectors. In such case the
green sector should have about half the area of the red sector, and the blue sector
be very much smaller than the green. The proportions will depend to some extent
upon the particular kind of sensitive film employed but they will be chiefly
regulated according to the length of exposure required for photographing the
several colours, an important point being that all the colours shall have an
equivalent amount of exposure, having regard to the fact that blue requires much
less exposure than green, and green less exposure than red.
Also instead of employing the disc 10 containing the liquids as above described,
I may employ the disc 10" shown in Figures 5 and 6. This disc is composed of
three differently. coloured sectors of single thicknesses of glass or other transparent
material fitted in a peripheral ring or bežil 15", and clamped between two
plates 17, 17 and fixed upon the axle 8 in the manner above described with
reference to the disc 10. In this arrangement the sectors are made of different
areas corresponding to the requisite exposures of the respective colours.
In taking a photograph, the disc 10 (or the disc 10" as the case may be) is
caused to revolve rapidly by turning the handle 14, so that the several coloured
parts of the disc will pass successively behind the objective 7 during one and
the same exposure.
In projecting the image upon a screen the transparency 22 obtained from the
negative (see Figure 7) of the photograph taken by means of the apparatus herein-
before described is projected through the lens 23 of a magic lantern 24 in which
a disc 10 composed of sectors similarly coloured to those of the disc 10 used in
taking the photograph, is revolved rapidly in front of the lens 23. The picture
appearing on the screen will show all the colours of the original scene or picture.
The disc 10 can be rotated by any suitable arrangement; in the arrangement
shown it is mounted on a horizontal axle 25 supported laterally of the lens piece 26
in a bracket 27. Rapid rotary motion is imparted to the disc 10 by means of a
cord 28 passing around a small cord pulley 29 keyed on the axle 25 and around
a large cord pulley 30 carried by a bracket 31 and provided with an operating
handle 32.
The coloured disc 10 shown in Figures 5 and 6 may also be constructed as a
lens, by dispensing with the central attachments, and the sectors being curved
to a common centre. This lens which does not rotate is employed alone in place
of the ordinary lens in both the camera or photographic apparatus and the magic
lantern or projecting apparatus.
In Figures 9 and 10, which illustrate this parti-colored lens, 33 represents
the lens; it is composed of three lens sectors having one common centre, arranged
in a suitably constructed holder 34. These lens sectors are colored in separate
colours, and the respective sizes of the sectors correspond to their respective colours
as herein before explained. The negative images producd by the several sectors
will be as it were intermingled with one another to form one single negative
image containing vibrations of the several colors. This image when transferred
to a transparency and projected upon a screen by means of an apparatus or
lantern having a corresponding parti-colored lens will reproduce the original scene
or picture in its natural colours. For some purposes the lens sectors may have
slightly different foci.
If it is not required that the picture obtained should be coloured I employ a
lens composed of several uncolored lens sectors having one common centre and
they should be of equal dimensions. The negative obtained bears, as is the case
when coloured lens sectors are used as many pictures as there are sectors these pictures

page_text: being as it were intermingled or superposed the result being that the positive
picture subsequently produced is softened and "retouching becomes practically
unnecessary.
""
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:―
1. The herein described method of taking photographic negatives, which
consists in taking a single negative through a transparent medium bearing
three or more primary colours, said colors being caused to pass rapidly in succes-
sion through the optical field of the apparatus during exposure of the negative,
substantially as described.
2. The herein described method of taking photographic negatives which
consists in taking a single negative through a lens which is built up of three
or more sectors, each of said sectors being colored with a different primary color,
and all of said sectors having a common centre, substantially as described.
3. The herein described method of reproducing a scene or picture in color which
consists in taking a single photographic negative as specified in Claim 1 or
Claim 2, then transferring the negative image to a transparency and then pro-
jecting said image from said transparency through a transparent medium of the
kind specified in Claim 1 or Claim 2 substantially as set forth.
4. As a new article of manufacture, a photographic negative such as is obtained
by the method specified in Claim 1 or Claim 2.
5. As a new article of manufacture, a photographic transparency such as is
obtained by transferring the negative specified in Claim 4 to a transparent
medium.
6. In apparatus for taking photographic negatives or projecting transparencies,
a transparent medium bearing three or more primary colors and means for impart-
ing motion thereto to cause said colors to travel rapidly and successively through
the optical field of the taking or projecting apparatus substantially as described.
7. In apparatus for taking photographic negatives or projecting transparencies,
a parti-colored lens composed of lens sectors having a common centre, substantially
as described and represented in Figures 9 and 10.
8. In apparatus for taking photographic negatives or projecting transparencies,
lens composed of several uncolored lens sectors having a common centre, sub-
stantially as described.
9. Apparatus for taking photographic negatives or projecting transparencies
constructed, arranged and operating substantially as herein described and shown
in the accompanying drawings.
Dated this 14th day of July 189.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.
9.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents.