Improvements in the Method of and Apparatus for Producing Photographs, and in Optical Lanterns for Displaying them, or the like.
Year: 1890

page_text: Date of Application, 28th Nov., 1890
Complete Specification Left, 28th Aug., 1891-Accepted, 10th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Method of and Apparatus for Producing
Photographs, and in Optical Lanterns for Displaying them, or
the like.
I ALBERT WILLIAM SCOTT, Photographer and Optical Lantern Exhibitor, of
Ashcombe Road, Weston-super-Mare, do hereby declare the nature of this invention
to be as follows :-
This invention for improvements in the method of and apparatus for producing
photographs and in optical lanterns for displaying them or the like has for its
object to photograph persons objects scenes or the like, and to project images of the
same on to a screen by a lime light or other suitable means either in a single
colour, light and shade, or in its true colours as may be desired and also to exhibit
complicated dioramic effects on a screen or otherwise and consists essentially in
photographing the object to be exhibited in three or more images each produced. by
rays of light of one colour (simple or compound) on a sensitised plate and in then pro-
jecting on to the screen each image in the particular colour corresponding to it or in
any colour or in light and shade and in causing these images to exactly register on
the screen so as to show a single image in its true colours or in any colour or colours
or in light and shade.
In one method of carrying this invention into practical effect, the object is
photographed in four places on the same plate, each photograph being produced by
rays of light of one colour only viz. red, green, blue, and violet the rays of light
from the other colours being stopped by coloured plates or other well known means.
Each photograph is produced by a separate lens or combination of lenses, the
diaphragms in the lenses being properly proportioned according to the sensitiveness
of the plate to the rays of light acting upon it. The four lenses are immoveable
with respect to each other and the camera is provided with partitions to prevent
the rays
of light passing through one lens from affecting the images corresponding
to the other lenses. The lenses are operated together and are covered by one large
cap so that all the images are exposed for the same length of time. The plate is
developed in the ordinary manner and should be made equal in density and details.
A positive is then obtained from the plate preferably by some process giving great
brilliancy and contrast. This positive plate is then ready for use in the special
lantern to be presently described. It is of course in black and white apparently
destitute of colours.
The lantern for projecting the four images in their own or other desired
colours on to the screen so that they exactly register to form one picture is
provided with either the same set of lenses used for obtaining the said images or
with similar set behind which is a weak focusing or registering lens, then the
plate containing the images to be projected on to the screen, then a condensor
consisting of a frame of four convex lenses, then a frame containing the four
coloured screens which impart the same or other desired colour to rays emanating
from the image as those by which it was originally taken, then the ordinary
lantern condensors throwing parallel beams of light behind which is arranged a
powerful lime light.
It will readily be seen that a lantern constructed as described above may be
used for most complicated dioramic effects by covering up one or more of the
four lenses. Also that the images may be taken by three or more separate
apparatus and be also projected on to the screen by three or more lanterns
adjusted so that the images all register on the screen, and that when taking
the negatives instead of increasing the size of the diaphragm according to the

page_text: sensitiveness of the plate the time of exposure may be increased. The coloured
screens are preferably of gelatine plates stained with suitable dyes.
The lantern and camera may be supported by means of rods passing through
holes in plates fixed at or near the bottom of the box which is used for packing
the lantern or camera and having spikes taking or screwing into holes in plates
fixed at or near the top of the box.
Photographs of persons taken by my improved apparatus give four (or other
number) of slightly differing images from which to select.
Dated this 28th day of November 1890.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Producing
Photographs, and in Optical Lanterns for Displaying them, or
the like.
I ALBERT WILLIAM SCOTT, Photographer and Optical Lantern Exhibitor, of
Ashcombe Road, Weston-super-Mare, 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 for improvements in the method of and apparatus for producing
photographs and in optical lanterns for displaying them or the like has for its
object to photograph persons objects scenes or the like, and to project images of
the same on to a screen by a lime light or other suitable means either in a single
colour, light and shade, or in its true colours as may be desired and also to exhibit
complicated dioramic effects on a screen or otherwise and consists essentially in
photographing the object to be exhibited in three or more images each produced by
rays of light of one colour (simple or compound) on a sensitised plate and in then
projecting on to the screen each image in the particular colour corresponding to it
or in any colour or in light and shade and in causing these images to exactly
register on the screen so as to show a single image in its true colours or, in any
colour or colours or in light and shade.
In one method of carrying this invention into practical effect the object is
photographed in four places on the same plate, each photograph being produced
by rays of light of one colour only viz. red, green, blue and violet the rays of light
from the other colours being stopped by coloured plates or other well known
means. Each photograph is produced by a separate lens or combination of lenses,
the diaphragm in the lens being properly proportioned according to the sensitiveness
of the plate to the rays of light of that particular colour corresponding to the lens.
The four lenses are immoveable with respect to each other and the camera is
provided with partitions to prevent the rays of light passing through one lens
from affecting the images corresponding to the other lenses.
The lenses are
operated together and are covered by one large cap so that all the images are
exposed for the same length of time. The plate is developed in the ordinary
manner and the four photographs should be made equal in density and details. A
positive is then obtained from the plate preferably by some process giving great
brilliancy and contrast. This positive plate is then ready for use in the special
lantern to be presently described. It is of course in black and white apparently
destitute of colours.
The lantern for projecting the four images in their own or other desired colours
on to the screen so that they exactly register to form one picture is provided with
either the same set of lenses used for obtaining the said images or with a similar
set behind which is a weak focusing or registering lens, then the plate containing
the images to be projected on to the screen, then a condensor consisting of a frame
of four convex lenses, then a frame. containing the four coloured screens which

page_text: impart the same or other desired colour to rays emanating from the image as those
by which it was originally taken, then the ordinary lantern condensors throwing
parallel beams of light behind which is arranged a powerful lime light.
It will readily be seen that a lantern constructed as described above may be
used for most complicated dioramic effects by covering up one or more of the four
lenses.
Photographs of persons taken by my improved apparatus give four (or other
number) of slightly differing images from which to select.
In the accompanying sheet of illustrative drawings,
Fig. 1 is a vertical section of the front of an optical lantern for displaying
photographs and the like in their natural colours constructed according to this
invention and
Fig. 2 is a front view and
Figs. 3 and 4 cross sections of the same.
Fig. 5 is a similar view to Fig. 1 showing a modified arrangement of lenses and,
Fig. 6 is a front elevation of the same.
The lantern is provided at the front with four ordinary photographic lenses a
fixed symmetrically within a tube fitted to slide in another tube c fixed to the
front of the body of the lantern. The tube is operated by means of the handle d
fixed to a half ring e pivotted to the outer ends of links connected at their inner
ends to the body of the lantern as shown at h so that they and the tube and
operating parts can readily be removed. Pins on the ends of the half ring e take
into holes in the tube b. By suitably operating the handle d the tube band with it
the lenses a can be protruded or withdrawn and be also revolved slightly to adjust
the pictures or images. The lenses a are immovably fixed in a plate g according to
a fixed template so that all sets shall be exact counterparts of one another. The
lenses are inserted and the cases in which the lenses are mounted pass through holes
in a plate fixed in the tube b as shown.
Within the tube c is a registering lens which can be slid along the tube c by
means of the rod m. Behind the tube e is a frame
which can be slid crosswise in
the body of the lantern in the ordinary manner. This frame is provided with
grooves in which the photographic slide o can be inserted and traversed across the
lantern in the ordinary manner. In a similar frame behind the frame n are four
lenses p symmetrically arranged as shown in Fig. 4 and at the back of these also
in a similar frame a colour screen q as shown in front elevation in Fig. 3.
Behind
the colour screen are the compound condensing lenses mounted in a frame and
inserted in position from the back in the ordinary manner. The focus for the light
is indicated at s.
The colour screen q may be made of four pieces of stained glass of the brightest
colours procurable ei. red, green, blue, and violet. If the glass is painted with
transparent varnish colours, the red glass may be formed by a mixture of rose
madder and gamboge; the green by a mixture of verdigris and yellow; the blue
by Prussian blue; and the violet by a mixture of mauve and French ultramarine.
The depth of the colours is adjusted so that their combined effect is to produce a
If the lenses
white light on the screen but spectroscopic tests are not necessary.
corresponding to the blue and violet are covered the light on the screen should be
bright yellow and if the blue and green lenses be covered over the light on the
screen should be a deep pink or magenta.
The camera is a multiple camera having four photographic lenses corresponding
to the lenses a of the lantern and arranged in a similar manner and is provided with
the usual fittings. The photographic lenses are also fitted with diaphragms whose
apertures correspond with the sensitiveness of the plate to the colours of the light
acting on the plate and admitted through the lenses. The light passing through
the lenses before acting on the plate is passed through coloured plates corresponding
to the plates q.of the lantern but the coloured plates must answer to spectroscopic
tests as follows:-The red screen is to be opaque to all colours except red: the

page_text: green screen is opaque to the blue and violet rays; the blue screen is opaque
to violet, green and yellow ys; the violet screen is opaque to blue, green and
yellow rays.
The red screen for the camera may be formed by transparent gelatine films of
deep ruby and lemon yellow and orange; the green screen by films of lemon yellow
and pale orange yellow; the blue screen by films of pale lemon yellow and violet ;
and the violet screen by films of violet and magenta or pale orange. As the
apertures in the diaphragms of the lenses corresponding to the green, blue and violet
lights are small in comparison with that corresponding to the red light as the plate
is not so sensitive to red light, the action of any red light admitted through these
screens may be neglected; if however a plate equally sensitive to red light were
obtainable then it would be necessary to cut off any red light passing through these
screens. The films are cut to sizes and cemented between two plates of clear glass.
The colour screen may be placed near to and in front of the plate.
In photographing small objects it is preferable to make the exposures through
the four lenses consecutive, the object being moved sideways or vertically the
distance between the centres of the lenses so as to be exactly opposite the required
lens.
Negatives made by this method consist of four pictures alike in outline, but
differing in density of the shading, arranged symmetrically on one plate. It is
obvious that similar negatives can be produced by arranging four duplicate outlines
symmetrically on glass or paper, and putting in the shading by handwork, corre-
sponding with the desired colours. These designs in black and white may be
reduced by ordinary photographic means to the proper size of lantern slides:
and when displayed by the special lantern front, will produce coloured pictures
ou the screen.
When ordinary slides are mixed up with slides prepared as above described, the
lantern may be provided with two interchangeable fronts fixed together and which
can be slid vertically before the source of light to effect the change, one front being
of the ordinary construction and the other constructed according to this invention.
In the modification shown in Figs. 5 and 6, the lenses a are pivotted to a plate y
fixed in the tube and can be adjusted by the cam operated by the handle x. in
this case the lens is dispensed with and the four lenses p are removed and placed
in the tube c and adjusted by the rod m.
It will be obvious that this invention may be modified in various ways without
departing from the nature of this invention.
I am aware that attempts have been made to display photographs in their true
colours by means of three separate lanterns which are arranged so that the images
projected exactly register on the screen.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
1. A multiple camera for producing photographs provided with a colour screen so
that different pictures or images are formed corresponding to the different colours
of the screen and the natural colours of the object or view substantially as
described.
2. A multiple camera for producing photographs provided with a colour screen
so that different images are formed corresponding to the different colours of the
screen and of the natural colours of the object or view and whose lenses are
provided with diaphragms having openings corresponding to the sensitiveness of
the plate to the action of lights of the colours of the corresponding parts of the
colour screen substantially as described.
3. A lantern slide in black and white having three or more images, similar in
outline, but with differences of local density, corresponding with the colours of the
original object view or design substantially as described.

page_text: 4. An optical lantern having one focus of light and capable of producing three
or more pictures in different colours on a screen and provided with means for
causing the said pictures to register on the screen substantially as described.
5. An optical lantern constructed substantially as described with reference to
Figs. 1 to 4 of the drawings.
6. An optical lantern constructed substantially as described with reference to
Figs. 5 and 6 of the drawings.
7. A colour screen for photographic camera constructed substantially as described
for the purpose specified.
8. A colour screen for an optical lantern constructed substantially as described
for the purpose specified.
Dated this 28th day of August 1891.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.